Revert "修复mp4_as_player设置为1时，on_stream_none_reader回调无效流信息的问题 (#4725)"

This reverts commit 6f9531c5fa.

src/Common/MediaSource.h

@@ -397,8 +397,7 @@ bool equalMediaTuple(const MediaTuple& a, const MediaTuple& b);
  */
 class MediaSource: public TrackSource, public std::enable_shared_from_this<MediaSource> {
 public:
-    static MediaSource &NullMediaSource(const MediaTuple &tuple = {"vhost", "app", "stream" });
-
+    static MediaSource& NullMediaSource();
     using Ptr = std::shared_ptr<MediaSource>;
 
     MediaSource(const std::string &schema, const MediaTuple& tuple);