message: Prevent arithmetic overflow in FTT computation.
  The fault tolerance threshold is specified in percent, but when
  multiplying the total weight by the percentage, we risk exceeding
  u64::MAX.
diff: @@ -420,9 +420,9 @@ where
  let validators: Validators<PublicKey> =
  validator_stakes.into_iter().map(scale_stake).collect();
  - let ftt = validators.total_weight()
  - * u64::from(self.highway_config().finality_threshold_percent)
  - / 100;
  + let total_weight = u128::from(validators.total_weight());
  + let ftt_percent = u128::from(self.highway_config().finality_threshold_percent);
  + let ftt = ((total_weight * ftt_percent / 100) as u64).into();
  // TODO: The initial round length should be the observed median of the switch block.
  let params = Params::new(
  seed,
  