修复由于识别不出关键帧而导致hls不能切片. (#1551)

2.修复由于丢弃sei帧导致ffplay不能正常播放

src/Extension/H264.h

@@ -138,7 +138,7 @@ private:
     void insertConfigFrame(const Frame::Ptr &frame);
 
 private:
-    bool _is_idr = false;
+    bool _insert_config_frame = false;
     int _width = 0;
     int _height = 0;
     float _fps = 0;