remove redundant call to load datamanager

Author: ravinkohli

autoPyTorch/pipeline/components/training/trainer/__init__.py

@@ -492,7 +492,7 @@ def _get_train_label(self, X: Dict[str, Any]) -> List[int]:
         Verifies and validates the labels from train split.
         """
         # Ensure that the split is not missing any class.
-        labels: List[int] = X['y_train'][X['backend'].load_datamanager().splits[X['split_id']][0]]
+        labels: List[int] = X['y_train'][X['train_indices']]
         if STRING_TO_TASK_TYPES[X['dataset_properties']['task_type']] in CLASSIFICATION_TASKS:
             unique_labels = len(np.unique(labels))
             if unique_labels < X['dataset_properties']['output_shape']: