message: transport: Move adding generated token before possibly getting a new packet
  The way it was, I think we would be adding tokens to the wrong packet, if
  more than one packet it generated in the loop.
diff: @@ -1007,6 +1007,9 @@ impl Connection {
  _ => is_crypto_packet,
  };
  frame.marshal(&mut d);
  + if let Some(t) = token {
  + tokens.push(t);
  + }
  assert!(d.written() <= self.pmtu);
  if d.written() == self.pmtu {
  // Filled this packet, get another one.
  @@ -1016,9 +1019,6 @@ impl Connection {
  ack_eliciting = false;
  is_crypto_packet = false;
  }
  - if let Some(t) = token {
  - tokens.push(t);
  - }
  }
  }
  self.generators = generators;
  