message: Allow keras.models.load_model to load models that were saved before weighted metrics was added.
diff: @@ -248,7 +248,7 @@ def load_model(filepath, custom_objects=None, compile=True): # pylint: disable=
  loss = convert_custom_objects(training_config['loss'])
  metrics = convert_custom_objects(training_config['metrics'])
  weighted_metrics = convert_custom_objects(
  - training_config['weighted_metrics'])
  + training_config.get('weighted_metrics', None))
  sample_weight_mode = training_config['sample_weight_mode']
  loss_weights = training_config['loss_weights']
  