Adding cancellation token WaitHandle to the list of handles we wait for to break out of the run loop.

Author: fabiocav

src/WebJobs.Script/Host/ScriptHostManager.cs

@@ -99,6 +99,7 @@ public ScriptHost Instance
                     // restarts are only happening on a single thread.
                     WaitHandle.WaitAny(new WaitHandle[] 
                     {
+                        cancellationToken.WaitHandle,
                         newInstance.RestartEvent,
                         _stopEvent
                     });