message: Add info message if we get a valid retry packet
  We don't yet actually retry but it's good to be
  clear why the connection is stuck, so it's not just a
  mystery.
diff: @@ -527,6 +527,7 @@ impl Connection {
  path.remote_cid = hdr.scid.expect("Retry pkt must have SCID");
  }
  }
  + qinfo!("received valid Retry, but we don't do anything with these yet.");
  self.retry_token = Some(token.clone());
  return Ok(());
  }
  