Setting ScriptHostManager state before ScriptHost disposal

Author: brettsam

src/WebJobs.Script/Host/ScriptHostManager.cs

@@ -174,6 +174,9 @@ public bool CanInvoke()
                         _stopEvent
                     });
 
+                    // Immediately set the state to Default, which causes CanInvoke() to return false.
+                    State = ScriptHostState.Default;
+
                     // Orphan the current host instance. We're stopping it, so it won't listen for any new functions
                     // it will finish any currently executing functions and then clean itself up.
                     // Spin around and create a new host instance.