remove collateral check from considerContract
remove collateral check from considerContract

I'm not sure this is the right way to handle this, but the current
collateral check will reject Renewed contracts. Something must be
done to prevent this.

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