Repository: intellij-rust/intellij-rust
Issue: Code folding option panel shows nothing

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## Environment

* **IntelliJ Rust plugin version:** 0.2.117.2856-201-nightly
* **Rust toolchain version:** 1.41.0 (5e1a79984 2020-01-27) x86_64-apple-darwin
* **IDE name and version:** IntelliJ IDEA 2020.1 EAP Ultimate Edition (IU-201.5259.13)
* **Operating system:** macOS 10.13.6

## Problem description

If IntelliJ Rust plugin is installed in your IDE, code folding options panel shows nothing and throws exception

<details><summary>Stacktrace</summary>

```
cannot create configurable component

java.lang.NullPointerException
	at java.base/java.util.Comparator.lambda$comparing$77a9974f$1(Comparator.java:469)
	at java.base/java.util.TimSort.binarySort(TimSort.java:296)
	at java.base/java.util.TimSort.sort(TimSort.java:221)
	at java.base/java.util.Arrays.sort(Arrays.java:1515)
	at java.base/java.util.ArrayList.sort(ArrayList.java:1749)
	at com.intellij.util.containers.JBIterable.sort(JBIterable.java:821)
	at com.intellij.application.options.editor.CodeFoldingConfigurable.createComponent(CodeFoldingConfigurable.java:56)
	at com.intellij.openapi.options.ex.ConfigurableWrapper.createComponent(ConfigurableWrapper.java:162)
	at com.intellij.openapi.options.ex.ConfigurableCardPanel.lambda$createConfigurableComponent$4(ConfigurableCardPanel.java:109)
	at com.intellij.openapi.application.impl.ApplicationImpl.runReadAction(ApplicationImpl.java:872)
	at com.intellij.openapi.application.ReadAction.compute(ReadAction.java:61)
	at com.intellij.openapi.options.ex.ConfigurableCardPanel.createConfigurableComponent(ConfigurableCardPanel.java:105)
	at com.intellij.openapi.options.ex.ConfigurableCardPanel.lambda$create$0(ConfigurableCardPanel.java:54)
	at com.intellij.openapi.application.impl.ApplicationImpl.runReadAction(ApplicationImpl.java:872)
	at com.intellij.openapi.application.ReadAction.compute(ReadAction.java:61)
	at com.intellij.openapi.options.ex.ConfigurableCardPanel.create(ConfigurableCardPanel.java:53)
	at com.intellij.openapi.options.newEditor.ConfigurableEditor$1.create(ConfigurableEditor.java:56)
	at com.intellij.openapi.options.newEditor.ConfigurableEditor$1.create(ConfigurableEditor.java:53)
	at com.intellij.ui.CardLayoutPanel.createValue(CardLayoutPanel.java:73)
	at com.intellij.ui.CardLayoutPanel.select(CardLayoutPanel.java:101)
	at com.intellij.ui.CardLayoutPanel.lambda$null$0(CardLayoutPanel.java:117)
	at com.intellij.openapi.application.TransactionGuardImpl$2.run(TransactionGuardImpl.java:198)
	at com.intellij.openapi.application.impl.ApplicationImpl.runIntendedWriteActionOnCurrentThread(ApplicationImpl.java:809)
	at com.intellij.openapi.application.impl.ApplicationImpl.lambda$invokeLater$4(ApplicationImpl.java:310)
	at com.intellij.openapi.application.impl.FlushQueue.doRun(FlushQueue.java:80)
	at com.intellij.openapi.application.impl.FlushQueue.runNextEvent(FlushQueue.java:128)
	at com.intellij.openapi.application.impl.FlushQueue.flushNow(FlushQueue.java:46)
	at java.desktop/java.awt.event.InvocationEvent.dispatch(InvocationEvent.java:313)
	at java.desktop/java.awt.EventQueue.dispatchEventImpl(EventQueue.java:776)
	at java.desktop/java.awt.EventQueue$4.run(EventQueue.java:727)
	at java.desktop/java.awt.EventQueue$4.run(EventQueue.java:721)
	at java.base/java.security.AccessController.doPrivileged(Native Method)
	at java.base/java.security.ProtectionDomain$JavaSecurityAccessImpl.doIntersectionPrivilege(ProtectionDomain.java:85)
	at java.desktop/java.awt.EventQueue.dispatchEvent(EventQueue.java:746)
	at com.intellij.ide.IdeEventQueue.defaultDispatchEvent(IdeEventQueue.java:971)
	at com.intellij.ide.IdeEventQueue._dispatchEvent(IdeEventQueue.java:844)
	at com.intellij.ide.IdeEventQueue.lambda$null$8(IdeEventQueue.java:442)
	at com.intellij.openapi.progress.impl.CoreProgressManager.computePrioritized(CoreProgressManager.java:729)
	at com.intellij.ide.IdeEventQueue.lambda$dispatchEvent$9(IdeEventQueue.java:441)
	at com.intellij.openapi.application.impl.ApplicationImpl.runIntendedWriteActionOnCurrentThread(ApplicationImpl.java:809)
	at com.intellij.ide.IdeEventQueue.dispatchEvent(IdeEventQueue.java:499)
	at java.desktop/java.awt.EventDispatchThread.pumpOneEventForFilters(EventDispatchThread.java:203)
	at java.desktop/java.awt.EventDispatchThread.pumpEventsForFilter(EventDispatchThread.java:124)
	at java.desktop/java.awt.EventDispatchThread.pumpEventsForFilter(EventDispatchThread.java:117)
	at java.desktop/java.awt.WaitDispatchSupport$2.run(WaitDispatchSupport.java:190)
	at java.desktop/java.awt.WaitDispatchSupport$4.run(WaitDispatchSupport.java:235)
	at java.desktop/java.awt.WaitDispatchSupport$4.run(WaitDispatchSupport.java:233)
	at java.base/java.security.AccessController.doPrivileged(Native Method)
	at java.desktop/java.awt.WaitDispatchSupport.enter(WaitDispatchSupport.java:233)
	at java.desktop/java.awt.Dialog.show(Dialog.java:1063)
	at com.intellij.openapi.ui.impl.DialogWrapperPeerImpl$MyDialog.show(DialogWrapperPeerImpl.java:708)
	at com.intellij.openapi.ui.impl.DialogWrapperPeerImpl.show(DialogWrapperPeerImpl.java:437)
	at com.intellij.openapi.ui.DialogWrapper.doShow(DialogWrapper.java:1706)
	at com.intellij.openapi.ui.DialogWrapper.show(DialogWrapper.java:1665)
	at com.intellij.ide.actions.ShowSettingsUtilImpl.showSettingsDialog(ShowSettingsUtilImpl.java:80)
	at com.intellij.ide.actions.ShowSettingsAction.perform(ShowSettingsAction.java:54)
	at com.intellij.ui.mac.MacOSApplicationProvider$Worker.lambda$null$1(MacOSApplicationProvider.java:75)
	at com.intellij.ui.mac.MacOSApplicationProvider$Worker.lambda$submit$7(MacOSApplicationProvider.java:172)
	at com.intellij.openapi.application.TransactionGuardImpl$2.run(TransactionGuardImpl.java:198)
	at com.intellij.openapi.application.impl.ApplicationImpl.runIntendedWriteActionOnCurrentThread(ApplicationImpl.java:809)
	at com.intellij.openapi.application.impl.ApplicationImpl.lambda$invokeLater$4(ApplicationImpl.java:310)
	at com.intellij.openapi.application.impl.FlushQueue.doRun(FlushQueue.java:80)
	at com.intellij.openapi.application.impl.FlushQueue.runNextEvent(FlushQueue.java:128)
	at com.intellij.openapi.application.impl.FlushQueue.flushNow(FlushQueue.java:46)
	at java.desktop/java.awt.event.InvocationEvent.dispatch(InvocationEvent.java:313)
	at java.desktop/java.awt.EventQueue.dispatchEventImpl(EventQueue.java:776)
	at java.desktop/java.awt.EventQueue$4.run(EventQueue.java:727)
	at java.desktop/java.awt.EventQueue$4.run(EventQueue.java:721)
	at java.base/java.security.AccessController.doPrivileged(Native Method)
	at java.base/java.security.ProtectionDomain$JavaSecurityAccessImpl.doIntersectionPrivilege(ProtectionDomain.java:85)
	at java.desktop/java.awt.EventQueue.dispatchEvent(EventQueue.java:746)
	at com.intellij.ide.IdeEventQueue.defaultDispatchEvent(IdeEventQueue.java:971)
	at com.intellij.ide.IdeEventQueue._dispatchEvent(IdeEventQueue.java:844)
	at com.intellij.ide.IdeEventQueue.lambda$null$8(IdeEventQueue.java:442)
	at com.intellij.openapi.progress.impl.CoreProgressManager.computePrioritized(CoreProgressManager.java:740)
	at com.intellij.ide.IdeEventQueue.lambda$dispatchEvent$9(IdeEventQueue.java:441)
	at com.intellij.openapi.application.impl.ApplicationImpl.runIntendedWriteActionOnCurrentThread(ApplicationImpl.java:809)
	at com.intellij.ide.IdeEventQueue.dispatchEvent(IdeEventQueue.java:499)
	at java.desktop/java.awt.EventDispatchThread.pumpOneEventForFilters(EventDispatchThread.java:203)
	at java.desktop/java.awt.EventDispatchThread.pumpEventsForFilter(EventDispatchThread.java:124)
	at java.desktop/java.awt.EventDispatchThread.pumpEventsForHierarchy(EventDispatchThread.java:113)
	at java.desktop/java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:109)
	at java.desktop/java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:101)
	at java.desktop/java.awt.EventDispatchThread.run(EventDispatchThread.java:90)
```

</details>

## Steps to reproduce
Open `Preferences | Editor | General | Code Folding` 

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Changed files:
src/main/kotlin/org/rust/ide/folding/RsCodeFoldingOptionsProvider.kt

diff --git a/src/main/kotlin/org/rust/ide/folding/RsCodeFoldingOptionsProvider.kt b/src/main/kotlin/org/rust/ide/folding/RsCodeFoldingOptionsProvider.kt
index 2b778bd4e..b50e645df 100644
--- a/src/main/kotlin/org/rust/ide/folding/RsCodeFoldingOptionsProvider.kt
+++ b/src/main/kotlin/org/rust/ide/folding/RsCodeFoldingOptionsProvider.kt
@@ -9,13 +9,13 @@ import com.intellij.application.options.editor.CodeFoldingOptionsProvider
 import com.intellij.openapi.options.BeanConfigurable
 
 class RsCodeFoldingOptionsProvider :
-    BeanConfigurable<RsCodeFoldingSettings>(RsCodeFoldingSettings.instance),
+    BeanConfigurable<RsCodeFoldingSettings>(RsCodeFoldingSettings.instance, "Rust"),
     CodeFoldingOptionsProvider {
 
     init {
         val settings = instance
         if (settings != null) {
-            checkBox("Rust one-line methods", settings::collapsibleOneLineMethods)
+            checkBox("One-line methods", settings::collapsibleOneLineMethods)
         }
     }
 }