message: Remove `Display` impl `todo!`
diff: @@ -70,7 +70,9 @@ impl Display for ControlAnnouncement {
  ControlAnnouncement::FatalError { file, line, msg } => {
  write!(f, "fatal error [{}:{}]: {}", file, line, msg)
  }
  - _ => todo!(),
  + ControlAnnouncement::QueueDump { .. } => {
  + write!(f, "dump event queue")
  + }
  }
  }
  }
  