message: set GSO as default batching mode
  Summary:
  Set GSO as the default. This will fallback to non-GSO in case we don't have
  GSO
diff: @@ -70,7 +70,7 @@ struct TransportSettings {
  // flowControlWindowFrequency * window if the flow control changes.
  uint16_t flowControlWindowFrequency{2};
  // batching mode
  - QuicBatchingMode batchingMode{QuicBatchingMode::BATCHING_MODE_NONE};
  + QuicBatchingMode batchingMode{QuicBatchingMode::BATCHING_MODE_GSO};
  // maximum number of packets we can batch
  // does not apply to BATCHING_MODE_NONE
  uint32_t batchingNum{kDefaultQuicBatchingNum};
  