fix help dialog for 'siac wallet send siafunds'
fix help dialog for 'siac wallet send siafunds'

mharkus/Sia,ericflo/Sia,ChrisSchinnerl/Sia,NebulousLabs/Sia,johnathanhowell/Sia,mnsl/Sia,MrStrong/Sia,ericflo/Sia,mharkus/Sia,MrStrong/Sia,rivine/rivine,Mingling94/Sia,rivine/rivine,NebulousLabs/Sia,mtlynch/Sia,ChrisSchinnerl/Sia,mnsl/Sia,mtlynch/Sia