Fixed ListenerListInst not being rebuild after unregistering a listener, causing calls to unregistered event listeners.

common/net/minecraftforge/event/ListenerList.java

@@ -209,7 +209,10 @@ public class ListenerList
         {
             for(ArrayList<IEventListener> list : priorities)
             {
-                list.remove(listener);
+                if (list.remove(listener))
+				{
+					rebuild = true;
+				}
             }
         }
     }