improve TestRenterLocalRepair
improve TestRenterLocalRepair

MrStrong/Sia,ChrisSchinnerl/Sia,mtlynch/Sia,mharkus/Sia,ericflo/Sia,NebulousLabs/Sia,ChrisSchinnerl/Sia,mharkus/Sia,MrStrong/Sia,NebulousLabs/Sia,mtlynch/Sia,ericflo/Sia