Fix for Index Out of Bounds Exception & update deps to work with Hudson 3.1.2

Freestyle builds with Maven3 build steps _and_ multiple build wrappers causes the following for me:

```java
[ERROR] Failure: java.lang.IndexOutOfBoundsException: Index: 1, Size: 1
FATAL: java.lang.IndexOutOfBoundsException: Index: 1, Size: 1
org.hudsonci.utils.tasks.OperationFailure: java.lang.IndexOutOfBoundsException: Index: 1, Size: 1
	at org.hudsonci.utils.tasks.PerformOperation.execute(PerformOperation.java:64)
	at org.hudsonci.maven.plugin.builder.MavenBuilder.perform(MavenBuilder.java:169)
	at hudson.tasks.BuildStepMonitor$1.perform(BuildStepMonitor.java:34)
	at hudson.model.AbstractBuild$AbstractRunner.perform(AbstractBuild.java:736)
	at hudson.model.Build$RunnerImpl.build(Build.java:181)
	at hudson.model.Build$RunnerImpl.doRun(Build.java:136)
	at hudson.model.AbstractBuild$AbstractRunner.run(AbstractBuild.java:524)
	at hudson.model.Run.run(Run.java:1450)
	at hudson.model.FreeStyleBuild.run(FreeStyleBuild.java:44)
	at hudson.model.ResourceController.execute(ResourceController.java:82)
	at hudson.model.Executor.run(Executor.java:137)
Caused by: java.lang.IndexOutOfBoundsException: Index: 1, Size: 1
	at java.util.ArrayList.rangeCheck(ArrayList.java:635)
	at java.util.ArrayList.get(ArrayList.java:411)
	at org.jfrog.hudson.plugins.artifactory.maven3extractor.MavenExtractorEnvironment.buildEnvVars(MavenExtractorEnvironment.java:125)
	at org.jfrog.hudson.plugins.artifactory.maven3extractor.Maven3ExtractorWrapper$1.buildEnvVars(Maven3ExtractorWrapper.java:339)
	at hudson.model.AbstractBuild.getEnvironment(AbstractBuild.java:846)
	at org.hudsonci.maven.plugin.builder.internal.PerformBuild.doExecute(PerformBuild.java:87)
	at org.hudsonci.utils.tasks.PerformOperation.execute(PerformOperation.java:50)
	... 10 more
```
My fix might not be perfect, but does remove this error.

I've also updated dependencies to work with Hudson 3.1.2 (latest at time of writing)