Don't inject ;meta(urb_front) if frontmatter is empty/nonexistent
Don't inject ;meta(urb_front) if frontmatter is empty/nonexistent

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