message: [discovery-proxy] fix unused variable warning in release build
diff: @@ -261,6 +261,8 @@ void DiscoveryProxy::OnHostDiscovered(const std::string &
  otDnssdQueryType type = otDnssdGetQueryTypeAndName(query, &queryName);
  otbrError splitError;
  + OTBR_UNUSED_VARIABLE(splitError);
  +
  if (type != OT_DNSSD_QUERY_TYPE_RESOLVE_HOST)
  {
  continue;
  