Api doesn't clear empty playlists thumbnail

Issue description:

New API changes local thumbnail, but doesn’t clear empty

Logs:

Upload description: Telrod11

Additional information:

 
I posted a video for you
 

Reproduction steps:

 
The log should show I played through a 139 item ringtone playlist, that would have incremented from 6 to 7.
Playlist 6 is now empty, but the thumbnail remains
 

Media provider:

Local device

Screenshots: