Fix 'different prevotes in same round'
Fix 'different prevotes in same round'


Former-commit-id: aea3f14a26a304b3d801153f98c6f6d8b495fd2f
alekseysidorov/exonum,alekseysidorov/exonum,alekseysidorov/exonum,exonum/exonum,exonum/exonum,alekseysidorov/exonum,exonum/exonum,exonum/exonum