message: Fix console connection cpu hog
  A `FuturesUnordered` poll returns Nones if it's empty which results in
  a spinning loop if there's no client connected.
diff: @@ -420,7 +420,7 @@ async fn handle_connections<AcceptConnection, Connection, Stream, Client, E>(
  let mut connections = FuturesUnordered::new();
  loop {
  select! {
  - _ = connections.next() => {/* removes closed connections */},
  + _ = connections.next(), if !connections.is_empty() => (), // removes closed connections
  // If event_tx is closed then the runtime is shutting down therefore no new connections
  // are accepted
  connection = accept(), if !event_tx.is_closed() && !stop.is_cancelled() => {
  