message: Remove redundant check for ack state empty
  Summary: removes the redundant check for ack states empty
diff: @@ -33,14 +33,15 @@ quic::StreamFrameMetaData makeStreamFrameMetaDataFromStreamBuffer(
  namespace quic {
  bool hasAcksToSchedule(const AckState& ackState) {
  - if (ackState.acks.empty()) {
  + folly::Optional<PacketNum> largestAckSend = largestAckToSend(ackState);
  + if (!largestAckSend) {
  return false;
  }
  if (!ackState.largestAckScheduled) {
  // Never scheduled an ack, we need to send
  return true;
  }
  - return *largestAckToSend(ackState) > *(ackState.largestAckScheduled);
  + return *largestAckSend > *(ackState.largestAckScheduled);
  }
  bool neverWrittenAcksBefore(const QuicConnectionStateBase& conn) {
  