further fix up difficulty adjustment code
further fix up difficulty adjustment code

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