message: Fix erroneous condition caused by merging
  Summary: This condition check is removed by (https://github.com/facebookincubator/mvfst/commit/c07c2158d96901a5e2c18d9d3428db44e427a035), but then added by (https://github.com/facebookincubator/mvfst/commit/a8d5c156a1236e026fd730721c6bea2cbd9d25fd).
diff: @@ -219,7 +219,7 @@ folly::Optional<CongestionController::LossEvent> detectLossPackets(
  break;
  }
  auto currentPacketNumberSpace = pkt.packet.header.getPacketNumberSpace();
  - if (currentPacketNumberSpace != pnSpace || pkt.metadata.isD6DProbe) {
  + if (currentPacketNumberSpace != pnSpace) {
  iter++;
  continue;
  }
  