修复FFmpeg拉流代理无法通过close_stream接口关闭的bug

src/Common/MediaSource.h

@@ -167,10 +167,15 @@ public:
         }
         listener->onNoneReader(*this);
     }
+
     virtual void setListener(const std::weak_ptr<MediaSourceEvent> &listener){
         _listener = listener;
     }
 
+    std::weak_ptr<MediaSourceEvent> getListener(){
+        return _listener;
+    }
+
     template <typename FUN>
     static void for_each_media(FUN && fun){
         lock_guard<recursive_mutex> lock(g_mtxMediaSrc);