fixed a stupid bug caused by a bad sanity check on group probabilities
fixed a stupid bug caused by a bad sanity check on group probabilities

jacekburys/csmith,Panos90/csmith,Panos90/csmith,DmitryOlshansky/dsmith,DmitryOlshansky/dsmith,jacekburys/csmith,natgla/csmith,Panos90/csmith,jacekburys/csmith,DmitryOlshansky/dsmith,natgla/csmith,Panos90/csmith,jacekburys/csmith,DmitryOlshansky/dsmith,natgla/csmith,natgla/csmith,jacekburys/csmith