fix playback of http://mariinsky.tv/online/20110928/archive-m3u8-aapl.ism/Manifest(format=m3u8-aapl)
fix potential mismatch between audio and video PIDs when switching between different levels.
level 0, AAC PID is 300
level 1, AVC PID is 300, AAC PID is 301
when switching from level 0 to level 1, AAC PID was not updated correctly, leading to playback issue
fix https://github.com/mangui/HLSprovider/issues/116