Fix a bug on music library path changing when previous path is deleted
Fix a bug on music library path changing when previous path is deleted

A bug prevented normally changing the music library path if the previously
selected library folder had been deleted (or it had otherwise became
unavailable).

Faldon/music,paulijar/music,paulijar/music,Faldon/music,paulijar/music,Faldon/music,Faldon/music,owncloud/music,owncloud/music,paulijar/music,Faldon/music,owncloud/music,owncloud/music,paulijar/music,owncloud/music