weather: fix precipitation display
weather: fix precipitation display

The `precipProbability` value ranges from 0 to 1, so to display
percentages we need to scale it up.

urbit/urbit,urbit/urbit,ngzax/urbit,jfranklin9000/urbit,ngzax/urbit,ngzax/urbit,ngzax/urbit,jfranklin9000/urbit,urbit/urbit,urbit/urbit,jfranklin9000/urbit,ngzax/urbit,urbit/urbit,jfranklin9000/urbit,ngzax/urbit,ngzax/urbit,jfranklin9000/urbit,jfranklin9000/urbit,urbit/urbit,jfranklin9000/urbit,urbit/urbit