message: Fix is_quorum.
diff: @@ -1332,13 +1332,13 @@ impl<C: Context + 'static> SimpleConsensus<C> {
  fn is_quorum(&self, vidxs: impl Iterator<Item = ValidatorIndex>) -> bool {
  let mut sum = self.faulty_weight();
  let quorum_threshold = self.quorum_threshold();
  - if sum >= quorum_threshold {
  + if sum > quorum_threshold {
  return true;
  }
  for vidx in vidxs {
  if !self.faults.contains_key(&vidx) {
  sum += self.weights[vidx];
  - if sum >= quorum_threshold {
  + if sum > quorum_threshold {
  return true;
  }
  }
  