message: qlog/client: Change qlog filenames to include dcid
  Just the origin is liable to get overwritten if URLs with the same origin
  are fetched multiple times. This could happen during QNS multiconnect
  test, for example.
diff: @@ -452,7 +452,13 @@ fn client(
  max_blocked_streams: args.max_blocked_streams,
  },
  );
  - client.set_qlog(qlog_new(args, hostname)?);
  +
  + let qlog_filename = format!(
  + "{}-{}",
  + hostname,
  + client.conn().path().unwrap().remote_cid()
  + );
  + client.set_qlog(qlog_new(args, &qlog_filename)?);
  let mut h = Handler {
  streams: HashMap::new(),
  @@ -466,10 +472,10 @@ fn client(
  Ok(())
  }
  -fn qlog_new(args: &Args, origin: &str) -> Res<Option<NeqoQlog>> {
  +fn qlog_new(args: &Args, filename: &str) -> Res<Option<NeqoQlog>> {
  if let Some(qlog_dir) = &args.qlog_dir {
  let mut qlog_path = qlog_dir.to_path_buf();
  - qlog_path.push(format!("{}.qlog", origin));
  + qlog_path.push(format!("{}.qlog", filename));
  let f = OpenOptions::new()
  .write(true)
  @@ -899,7 +905,10 @@ mod old {
  client.set_ciphers(&ciphers)?;
  }
  - client.set_qlog(qlog_new(args, origin)?);
  + client.set_qlog(qlog_new(
  + args,
  + &format!("{}-{}", origin, client.path().unwrap().remote_cid()),
  + )?);
  let mut h = HandlerOld {
  streams: HashMap::new(),
  