mediafile: Catch IndexError when file has empty list tag
mediafile: Catch IndexError when file has empty list tag

Fixes #913

moodboom/beets,randybias/beets,ruippeixotog/beets,pkess/beets,Andypsamp/CODjunit,kareemallen/beets,bj-yinyan/beets,multikatt/beets,sadatay/beets,mathstuf/beets,madmouser1/beets,Wen777/beets,shamangeorge/beets,mried/beets,mathstuf/beets,swt30/beets,sampsyo/beets,xsteadfastx/beets,imsparsh/beets,parapente/beets,shanemikel/beets,moodboom/beets,pkess/beets,gabrielaraujof/beets,asteven/beets,kareemallen/beets,dfc/beets,asteven/beets,beetbox/beets,Freso/beets,pkess/beets,shanemikel/beets,multikatt/beets,marcuskrahl/beets,mosesfistos1/beetbox,lengtche/beets,arabenjamin/beets,drm00/beets,bj-yinyan/beets,sadatay/beets,jmwatte/beets,SusannaMaria/beets,beetbox/beets,ttsda/beets,jackwilsdon/beets,mosesfistos1/beetbox,marcuskrahl/beets,kelvinhammond/beets,tima/beets,dfc/beets,imsparsh/beets,ttsda/beets,bj-yinyan/beets,kareemallen/beets,Andypsamp/CODfinalJUNIT,lengtche/beets,untitaker/beets,Kraymer/beets,artemutin/beets,LordSputnik/beets,Dishwishy/beets,diego-plan9/beets,jcoady9/beets,jcoady9/beets,Andypsamp/CODjunit,ibmibmibm/beets,m-urban/beets,swt30/beets,ibmibmibm/beets,Kraymer/beets,lightwang1/beets,ttsda/beets,moodboom/beets,madmouser1/beets,MyTunesFreeMusic/privacy-policy,MyTunesFreeMusic/privacy-policy,jackwilsdon/beets,Andypsamp/CODfinalJUNIT,m-urban/beets,mried/beets,ibmibmibm/beets,YetAnotherNerd/beets,ruippeixotog/beets,xsteadfastx/beets,Wen777/beets,jackwilsdon/beets,andremiller/beets,mried/beets,jmwatte/beets,shanemikel/beets,xsteadfastx/beets,gabrielaraujof/beets,YetAnotherNerd/beets,beetbox/beets,YetAnotherNerd/beets,Andypsamp/CODjunit,tima/beets,lengtche/beets,LordSputnik/beets,SusannaMaria/beets,lightwang1/beets,arabenjamin/beets,lightwang1/beets,PierreRust/beets,Dishwishy/beets,Freso/beets,imsparsh/beets,untitaker/beets,parapente/beets,jackwilsdon/beets,shanemikel/beets,untitaker/beets,shamangeorge/beets,m-urban/beets,gabrielaraujof/beets,YetAnotherNerd/beets,Kraymer/beets,tima/beets,tima/beets,parapente/beets,Andypsamp/CODfinalJUNIT,randybias/beets,parapente/beets,jcoady9/beets,LordSputnik/beets,MyTunesFreeMusic/privacy-policy,kelvinhammond/beets,asteven/beets,Andypsamp/CODjunit,shamangeorge/beets,randybias/beets,kelvinhammond/beets,SusannaMaria/beets,MyTunesFreeMusic/privacy-policy,andremiller/beets,drm00/beets,ttsda/beets,PierreRust/beets,Andypsamp/CODjunit,kareemallen/beets,drm00/beets,moodboom/beets,jcoady9/beets,sampsyo/beets,Andypsamp/CODfinalJUNIT,multikatt/beets,mosesfistos1/beetbox,diego-plan9/beets,madmouser1/beets,xsteadfastx/beets,artemutin/beets,mathstuf/beets,m-urban/beets,bj-yinyan/beets,pkess/beets,LordSputnik/beets,drm00/beets,marcuskrahl/beets,mried/beets,Kraymer/beets,lengtche/beets,marcuskrahl/beets,SusannaMaria/beets,mosesfistos1/beetbox,dfc/beets,diego-plan9/beets,ruippeixotog/beets,lightwang1/beets,randybias/beets,diego-plan9/beets,sadatay/beets,Freso/beets,mathstuf/beets,beetbox/beets,madmouser1/beets,Freso/beets,ibmibmibm/beets,PierreRust/beets,sampsyo/beets,Wen777/beets,sadatay/beets,Dishwishy/beets,Dishwishy/beets,sampsyo/beets,PierreRust/beets,swt30/beets,andremiller/beets,jmwatte/beets,artemutin/beets,swt30/beets,arabenjamin/beets,Andypsamp/CODfinalJUNIT,kelvinhammond/beets,asteven/beets,jmwatte/beets,gabrielaraujof/beets,imsparsh/beets,dfc/beets,artemutin/beets,untitaker/beets,arabenjamin/beets,shamangeorge/beets,multikatt/beets,ruippeixotog/beets