NPE is thrown from VMConnection

[andrei.eremeev]

Hi REPL team,

 From times to times NPE is thrown from VMConnection, but none of tests 
fails.
It looks like VMConnection is accessed from several threads. If is true, 
synchronization should be added.

Exception in thread "event-handler" java.lang.NullPointerException
         at impl.VMConnection.disposeVM(VMConnection.java:379)
         at impl.JDIEnv.shutdown(JDIEnv.java:57)
         at impl.JDIEventHandler.handleExitEvent(JDIEventHandler.java:129)
         at impl.JDIEventHandler.handleEvent(JDIEventHandler.java:109)
         at impl.JDIEventHandler.run(JDIEventHandler.java:71)
         at java.lang.Thread.run(Thread.java:745)

Andrei Eremeev