Muting the presenter stream of 2 tracks in the video editor causes no audio being played back in the player
1. Open https://stable.opencast.org/admin-ng/index.html
2. Klick on the scissors, click on the "Tracks" tab and mute the audio of of the presenter.
3. Publish the package to Engange and wait until it is published.
4. Open the video in Engange.
Result: No audio is played back.
Expected result: Audio from track which is wasn't muted is played back.