Revert "use +mur in place of +mug"
Revert "use +mur in place of +mug"

This reverts commit 5b4ab145cc532367dbb316a2efcc4dc57669f461.

urbit/urbit,urbit/urbit,ngzax/urbit,jfranklin9000/urbit,joemfb/arvo,jfranklin9000/urbit,ngzax/urbit,ngzax/urbit,belisarius222/arvo,urbit/urbit,ngzax/urbit,ngzax/urbit,urbit/urbit,jfranklin9000/urbit,jfranklin9000/urbit,ngzax/urbit,urbit/urbit,jfranklin9000/urbit,urbit/urbit,jfranklin9000/urbit,jfranklin9000/urbit,ngzax/urbit,joemfb/arvo,urbit/urbit,belisarius222/arvo