Fix: try to compute the PoW until a handicap of 8
Fix: try to compute the PoW until a handicap of 8

duniter/duniter,blaurent49/duniter,duniter/duniter,duniter/duniter,duniter/duniter,duniter/duniter,blaurent49/duniter,blaurent49/duniter,blaurent49/duniter,duniter/duniter