fix raw dataset features

run_speech_recognition_seq2seq_streaming.py

@@ -376,7 +376,7 @@ def load_maybe_streaming_dataset(dataset_names, dataset_config_names, split="tra
         ):
             for split_name in split_names.split("+"):
                 dataset = load_dataset(dataset_name, dataset_config_name, split=split_name, streaming=streaming, **kwargs)                    
-                raw_datasets_features = list(next(iter(dataset.values())).features.keys())
+                raw_datasets_features = list(dataset.features.keys())
                 if column_names[0] not in raw_datasets_features:
                     if len(column_names) == 1 or column_names[1] not in raw_datasets_features:
                         raise ValueError("Column name not found in dataset.")