Import beets.ui in discogs plugin
Import beets.ui in discogs plugin

The discogs plugin uses beets.ui but did not explicitely import it,
which might cause it to crash when used in standalone.

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