message: Don't log a warning if proposal arrives in wrong round.
  A delayed proposal can arrive in a later round; that's not a reason to
  log at WARN level.
diff: use std::fmt::{self, Debug};
  -use tracing::{error, warn};
  +use tracing::{error, trace, warn};
  use super::{
  evidence::Evidence,
  @@ -242,9 +242,9 @@ impl<C: Context> ActiveValidator<C> {
  }
  let r_id = state::round_id(timestamp, self.round_exp(state, timestamp));
  if vote.timestamp != r_id {
  - warn!(
  + trace!(
  %vote.timestamp, %r_id,
  - "received proposal from unexpected round",
  + "not confirming proposal: wrong round",
  );
  return false;
  }
  