Glacier2 SessionHelper Unhandled CommunicatorDestroyedException

[pepone]

We get this failure with the latest ice-ci-centos-el7-dev-3.7

testing SessionHelper connect with wrong userid/password... ok
testing SessionHelper connect interrupt... Unhandled exception. Ice.CommunicatorDestroyedException
   at IceInternal.Instance.proxyFactory() in /home/vagrant/workspace/ice/3.7/csharp/src/Ice/Instance.cs:line 146
   at Ice.CommunicatorI.stringToProxy(String s) in /home/vagrant/workspace/ice/3.7/csharp/src/Ice/CommunicatorI.cs:line 59
   at Glacier2.SessionHelper.<>c__DisplayClass15_0.<connectImpl>b__0() in /home/vagrant/workspace/ice/3.7/csharp/src/Glacier2/SessionHelper.cs:line 392
   at System.Threading.ThreadHelper.ThreadStart_Context(Object state)
   at System.Threading.ExecutionContext.RunInternal(ExecutionContext executionContext, ContextCallback callback, Object state)
--- End of stack trace from previous location where exception was thrown ---
   at System.Threading.ExecutionContext.RunInternal(ExecutionContext executionContext, ContextCallback callback, Object state)
   at System.Threading.ThreadHelper.ThreadStart()

Seems like a bug, we should move the uncheckedCast inside the try/catch block bellow

ice/csharp/src/Glacier2/SessionHelper.cs

Lines 392 to 393 in b79c989

	Ice.RouterFinderPrx finder =
	Ice.RouterFinderPrxHelper.uncheckedCast(_communicator.stringToProxy(_finderStr));