message: Fix era end calculation.
  The earliest era end is the _maximum_ of the end time based on the
  configured minimum duration and the one based on the minimum round
  length and height.
diff: @@ -195,7 +195,7 @@ where
  + self
  .highway_config
  .era_duration
  - .min(params.min_round_len() * params.end_height());
  + .max(params.min_round_len() * params.end_height());
  let should_activate =
  min_end_time >= timestamp && validators.iter().any(|v| *v.id() == our_id);
  