%gall diff spec fix
%gall diff spec fix

`%gall` was unnecessarily specializing diff types.

urbit/urbit,urbit/urbit,urbit/urbit,joemfb/arvo,belisarius222/arvo,cgyarvin/arvo,jfranklin9000/urbit,Fang-/arvo,ngzax/urbit,urbit/urbit,jfranklin9000/urbit,ngzax/urbit,urbit/urbit,cgyarvin/arvo,belisarius222/arvo,ngzax/urbit,jfranklin9000/urbit,solri/arvo,ngzax/urbit,urbit/urbit,ngzax/urbit,ngzax/urbit,joemfb/arvo,urbit/urbit,ohAitch/arvo,ohAitch/arvo,jfranklin9000/urbit,jfranklin9000/urbit,ngzax/urbit,jfranklin9000/urbit,jfranklin9000/urbit