Fixed terminoloy

Runtime/Events/OnMessageEvent.cs

 
         void OnDisable()
         {
-            Messager.UnregisterEvent(MessageName, Execute);
+            Messager.RemoveMessage(MessageName, Execute);
         }
 
         void Execute()

Runtime/Messager/Messager.cs

                 m_RegisteredMessages[eventName] += message;
         }
 
-        public static void UnregisterEvent(string eventName, Message message)
+        public static void RemoveMessage(string eventName, Message message)
         {
             var currentEvent = m_RegisteredMessages[eventName];
             currentEvent -= message;