Edited Issue: Assertion on attach debugger (node.js) [807]

Debug Build CL1206806

I got this assert when I tried to attach the debugger to my azure web site from VWD 2013, published debug and web sockets enabled in portal.

I've only seen it once.
```
---------------------------
Assertion Failed: Abort=Quit, Retry=Debug, Ignore=Continue
---------------------------
Invalid response identifier '1'



at Microsoft.NodejsTools.Debugger.Communication.DebuggerClient.HandleResponseMessage(JObject message)

at Microsoft.NodejsTools.Debugger.Communication.DebuggerClient.OnOutputMessage(Object sender, MessageEventArgs args)

at Microsoft.NodejsTools.Debugger.Communication.DebuggerConnection.<ReadStreamAsync>d__d.MoveNext()

at System.Runtime.CompilerServices.AsyncMethodBuilderCore.MoveNextRunner.InvokeMoveNext(Object stateMachine)

at System.Threading.ExecutionContext.RunInternal(ExecutionContext executionContext, ContextCallback callback, Object state, Boolean preserveSyncCtx)

at System.Threading.ExecutionContext.Run(ExecutionContext executionContext, ContextCallback callback, Object state, Boolean preserveSyncCtx)

at System.Runtime.CompilerServices.AsyncMethodBuilderCore.MoveNextRunner.Run()

at System.Threading.Tasks.AwaitTaskContinuation.RunOrScheduleAction(Action action, Boolean allowInlining, Task& currentTask)

at System.Threading.Tasks.Tas......

<truncated>
---------------------------
Abort Retry Ignore
---------------------------
```