播放器新增schema参数支持指定拉流协议

src/Common/config.cpp

@@ -415,6 +415,7 @@ const string kWaitTrackReady = "wait_track_ready";
 const string kPlayTrack = "play_track";
 const string kProxyUrl = "proxy_url";
 const string kRtspSpeed = "rtsp_speed";
+const string kSchema = "schema";
 const string kLatency = "latency";
 const string kPassPhrase = "passPhrase";
 const string kCustomHeader = "custom_header";