fix compile error

Runtime/IMessageSender.cs

@@ -55,10 +55,10 @@ namespace DofLibrary
         /// 发送 AllLevelEnd 所有关卡结束 消息
         /// </summary>
         void AllLevelEnd(float timeSpent);
-        
+
         /// <summary>
         /// 发送心跳包
         /// </summary>
-        void Heartbeat(long timestamp)
+        void Heartbeat(long timestamp);
     }
 }