message: [network] Simplify check for peer actor event loop shutdown
  Closes:
  Approved by: bmwill
diff: @@ -868,8 +868,7 @@ where
  let mut substream_rx = self.connection.listen_for_inbound().fuse();
  let mut pending_outbound_substreams = FuturesUnordered::new();
  let mut pending_inbound_substreams = FuturesUnordered::new();
  -
  - loop {
  + while !self.shutdown {
  futures::select! {
  maybe_req = self.requests_rx.next() => {
  if let Some(request) = maybe_req {
  @@ -923,10 +922,6 @@ where
  },
  complete => unreachable!(),
  }
  -
  - if self.shutdown {
  - break;
  - }
  }
  debug!(
  "Peer actor '{}' shutdown",
  