[JENKINS-23522] - Fix Circular Call

Fix Circular call suspected under Youtrack Jenkins Plugin development.

Stack:
```
java.lang.StackOverflowError
	at java.lang.StringCoding$StringEncoder.encode(StringCoding.java:304)
	at java.lang.StringCoding.encode(StringCoding.java:344)
	at java.lang.String.getBytes(String.java:916)
	at java.io.UnixFileSystem.getBooleanAttributes0(Native Method)
	at java.io.UnixFileSystem.getBooleanAttributes(UnixFileSystem.java:242)
	at java.io.File.exists(File.java:813)
	at sun.misc.URLClassPath$FileLoader.getResource(URLClassPath.java:1080)
	at sun.misc.URLClassPath$FileLoader.findResource(URLClassPath.java:1047)
	at sun.misc.URLClassPath.findResource(URLClassPath.java:176)
	at java.net.URLClassLoader$2.run(URLClassLoader.java:551)
	at java.net.URLClassLoader$2.run(URLClassLoader.java:549)
	at java.security.AccessController.doPrivileged(Native Method)
	at java.net.URLClassLoader.findResource(URLClassLoader.java:548)
	at org.eclipse.jetty.webapp.WebAppClassLoader.getResource(WebAppClassLoader.java:356)
	at java.net.URLClassLoader.getResourceAsStream(URLClassLoader.java:227)
	at javax.xml.parsers.SecuritySupport$4.run(SecuritySupport.java:94)
	at java.security.AccessController.doPrivileged(Native Method)
	at javax.xml.parsers.SecuritySupport.getResourceAsStream(SecuritySupport.java:87)
	at javax.xml.parsers.FactoryFinder.findJarServiceProvider(FactoryFinder.java:283)
	at javax.xml.parsers.FactoryFinder.find(FactoryFinder.java:255)
	at javax.xml.parsers.SAXParserFactory.newInstance(SAXParserFactory.java:126)
	at org.jenkinsci.plugins.youtrack.youtrackapi.YouTrackServer.getProjects(YouTrackServer.java:290)
	at org.jenkinsci.plugins.youtrack.YouTrackSCMListener.onChangeLogParsed(YouTrackSCMListener.java:40)
	at hudson.model.listeners.SCMListener.onChangeLogParsed(SCMListener.java:113)
	at hudson.model.listeners.SCMListener.onChangeLogParsed(SCMListener.java:119)
	at org.jenkinsci.plugins.youtrack.YouTrackSCMListener.onChangeLogParsed(YouTrackSCMListener.java:84)
	at hudson.model.listeners.SCMListener.onChangeLogParsed(SCMListener.java:113)
	at hudson.model.listeners.SCMListener.onChangeLogParsed(SCMListener.java:119)
	at org.jenkinsci.plugins.youtrack.YouTrackSCMListener.onChangeLogParsed(YouTrackSCMListener.java:84)
	at hudson.model.listeners.SCMListener.onChangeLogParsed(SCMListener.java:113)
	at hudson.model.listeners.SCMListener.onChangeLogParsed(SCMListener.java:119)
	at org.jenkinsci.plugins.youtrack.YouTrackSCMListener.onChangeLogParsed(YouTrackSCMListener.java:84)
	at hudson.model.listeners.SCMListener.onChangeLogParsed(SCMListener.java:113)
	at hudson.model.listeners.SCMListener.onChangeLogParsed(SCMListener.java:119)
	at org.jenkinsci.plugins.youtrack.YouTrackSCMListener.onChangeLogParsed(YouTrackSCMListener.java:84)
	at hudson.model.listeners.SCMListener.onChangeLogParsed(SCMListener.java:113)
	at hudson.model.listeners.SCMListener.onChangeLogParsed(SCMListener.java:119)
	at org.jenkinsci.plugins.youtrack.YouTrackSCMListener.onChangeLogParsed(YouTrackSCMListener.java:84)
	at hudson.model.listeners.SCMListener.onChangeLogParsed(SCMListener.java:113)
	at hudson.model.listeners.SCMListener.onChangeLogParsed(SCMListener.java:119)
	at org.jenkinsci.plugins.youtrack.YouTrackSCMListener.onChangeLogParsed(YouTrackSCMListener.java:84)
	at hudson.model.listeners.SCMListener.onChangeLogParsed(SCMListener.java:113)
	at hudson.model.listeners.SCMListener.onChangeLogParsed(SCMListener.java:119)
	at org.jenkinsci.plugins.youtrack.YouTrackSCMListener.onChangeLogParsed(YouTrackSCMListener.java:84)
	at hudson.model.listeners.SCMListener.onChangeLogParsed(SCMListener.java:113)
	at hudson.model.listeners.SCMListener.onChangeLogParsed(SCMListener.java:119)
```