message: [consensus] Add better expect message
  The message right above it says the exact same thing
  Closes:
  Approved by: davidiw
diff: @@ -131,7 +131,7 @@ impl Vote {
  if let Some(timeout_signature) = &self.timeout_signature {
  timeout_signature
  .verify(validator, self.author(), self.timeout().hash())
  - .context("Fail to verify Vote")?;
  + .context("Fail to verify Timeout Vote")?;
  }
  Ok(())
  }
  