mpd: 'list "artist" ""' should not generate an invalid query
mpd: 'list "artist" ""' should not generate an invalid query

tkem/mopidy,mokieyue/mopidy,hkariti/mopidy,bencevans/mopidy,glogiotatidis/mopidy,diandiankan/mopidy,mokieyue/mopidy,bacontext/mopidy,ZenithDK/mopidy,SuperStarPL/mopidy,adamcik/mopidy,hkariti/mopidy,jcass77/mopidy,bacontext/mopidy,ali/mopidy,vrs01/mopidy,rawdlite/mopidy,mopidy/mopidy,ZenithDK/mopidy,diandiankan/mopidy,diandiankan/mopidy,glogiotatidis/mopidy,ZenithDK/mopidy,ali/mopidy,ZenithDK/mopidy,quartz55/mopidy,jodal/mopidy,jodal/mopidy,vrs01/mopidy,quartz55/mopidy,dbrgn/mopidy,mopidy/mopidy,pacificIT/mopidy,tkem/mopidy,dbrgn/mopidy,bencevans/mopidy,kingosticks/mopidy,rawdlite/mopidy,jcass77/mopidy,dbrgn/mopidy,mokieyue/mopidy,quartz55/mopidy,bencevans/mopidy,dbrgn/mopidy,swak/mopidy,jodal/mopidy,SuperStarPL/mopidy,vrs01/mopidy,bacontext/mopidy,hkariti/mopidy,jmarsik/mopidy,mokieyue/mopidy,quartz55/mopidy,ali/mopidy,tkem/mopidy,SuperStarPL/mopidy,hkariti/mopidy,pacificIT/mopidy,jmarsik/mopidy,adamcik/mopidy,mopidy/mopidy,rawdlite/mopidy,jmarsik/mopidy,swak/mopidy,pacificIT/mopidy,bacontext/mopidy,swak/mopidy,jmarsik/mopidy,diandiankan/mopidy,pacificIT/mopidy,swak/mopidy,ali/mopidy,kingosticks/mopidy,kingosticks/mopidy,rawdlite/mopidy,tkem/mopidy,bencevans/mopidy,glogiotatidis/mopidy,SuperStarPL/mopidy,adamcik/mopidy,jcass77/mopidy,vrs01/mopidy,glogiotatidis/mopidy