fix the bug of media thread. (#1215)
fix the bug of media thread. (#1215)


awslabs/amazon-kinesis-video-streams-webrtc-sdk-c,awslabs/amazon-kinesis-video-streams-webrtc-sdk-c,awslabs/amazon-kinesis-video-streams-webrtc-sdk-c,awslabs/amazon-kinesis-video-streams-webrtc-sdk-c