docs: Remove old cruft from Debian package page
docs: Remove old cruft from Debian package page

Part of #1398

mokieyue/mopidy,vrs01/mopidy,vrs01/mopidy,jodal/mopidy,jodal/mopidy,jcass77/mopidy,adamcik/mopidy,mokieyue/mopidy,jcass77/mopidy,kingosticks/mopidy,mopidy/mopidy,jcass77/mopidy,jodal/mopidy,vrs01/mopidy,tkem/mopidy,tkem/mopidy,mokieyue/mopidy,kingosticks/mopidy,tkem/mopidy,vrs01/mopidy,kingosticks/mopidy,adamcik/mopidy,mopidy/mopidy,ZenithDK/mopidy,tkem/mopidy,adamcik/mopidy,ZenithDK/mopidy,ZenithDK/mopidy,ZenithDK/mopidy,mokieyue/mopidy,mopidy/mopidy