Subsonic: Fix starring information not being present on artist list
Subsonic: Fix starring information not being present on artist list

The `starred` column was not being selected by ArtistMapper when
querying the artist data.

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