Fix deadlock in NetworkManager when network peer returns invalid event type

#1992

Source/Engine/Networking/NetworkManager.cpp

@@ -382,7 +382,8 @@ void NetworkManagerService::Update()
 
     // Process network messages
     NetworkEvent event;
-    while (peer->PopEvent(event))
+    bool eventIsValid = true;
+    while (peer->PopEvent(event) && eventIsValid)
     {
         switch (event.EventType)
         {
@@ -472,6 +473,9 @@ void NetworkManagerService::Update()
             }
             peer->RecycleMessage(event.Message);
             break;
+        default:
+            eventIsValid = false;
+            break;
         }
     }