message: add MESSAGE to show number of datareader workers
diff: @@ -1258,6 +1258,7 @@ static void create_pipeline_internal(std::shared_ptr<IDataReader>& data_reader,
  format == DataReaderType_t::Parquet ? resource_manager->get_local_gpu_count() : 12;
  const int num_workers = get_value_from_json_soft<int>(j, "num_workers", num_workers_default);
  #endif
  + MESSAGE_("Num of DataReader workers: " + std::to_string(num_workers));
  std::vector<DataReaderSparseParam> data_reader_sparse_param_array;
  