message: [Consensus][small] Initialize pacemaker round deadline
  We used to have round deadline initialized to `None`, but it created flakiness for event processing test because in some cases the `current_round_deadline` would be called before Pacemaker would finish its initialization. (Note that it wouldn't happen in real life because the whole process is jumpstarted by Pacemaker)
diff: @@ -121,7 +121,7 @@ struct LocalPacemakerInner {
  // it changes
  current_round: Round,
  // Approximate deadline when current round ends
  - current_round_deadline: Option<Instant>,
  + current_round_deadline: Instant,
  // Service for timer
  time_service: Arc<dyn TimeService>,
  // To send new round events.
  @@ -172,7 +172,7 @@ impl LocalPacemakerInner {
  highest_committed_round,
  highest_qc_round,
  current_round,
  - current_round_deadline: None,
  + current_round_deadline: Instant::now(),
  time_service,
  new_round_events_sender,
  local_timeout_sender,
  @@ -257,7 +257,7 @@ impl LocalPacemakerInner {
  let timeout = self
  .time_interval
  .get_round_duration(round_index_after_committed_round);
  - self.current_round_deadline = Some(Instant::now() + timeout);
  + self.current_round_deadline = Instant::now() + timeout;
  timeout
  }
  @@ -392,11 +392,7 @@ impl LocalPacemaker {
  impl Pacemaker for LocalPacemaker {
  fn current_round_deadline(&self) -> Instant {
  - self.inner
  - .read()
  - .unwrap()
  - .current_round_deadline
  - .expect("Round deadline was not set")
  + self.inner.read().unwrap().current_round_deadline
  }
  fn current_round(&self) -> Round {
  