message: fix where we update the sig offset when we view change
diff: @@ -1896,6 +1896,8 @@ void Replica::process_new_view(Seqno min, Digest d, Seqno max, Seqno ms)
  next_pp_seqno = max - 1;
  + pbft::GlobalState::get_replica().set_next_expected_sig_offset();
  +
  // Call mark_stable to ensure there is space for the pre-prepares
  // and prepares that are inserted in the log below.
  mark_stable(last_executed, last_executed >= ms);
  @@ -2046,7 +2048,6 @@ void Replica::rollback_to_globally_comitted()
  "Roll back done, last tentative execute and last executed are {} {}",
  last_tentative_execute,
  last_executed);
  - pbft::GlobalState::get_replica().set_next_expected_sig_offset();
  }
  }
  