AttributeError : 'Conv2D' object has no attribute 'get_config'

Question

I'm trying to run fgsm attack on mnist dataset. I'm getting 'object has no attribute' error:
I used: python 2 (in google colab) Keras==2.1.3 tensorflow==1.14.0

I also run it with keras==1.2 and keras==2.1.5 , I also chenged get_config into _get_config, However, all runs fail.

Unit_keras.py is here: https://github.com/tensorflow/cleverhans/blob/master/cleverhans/utils_keras.py
I also used : https://github.com/tensorflow/cleverhans/blob/6b065c4507f50e2545c009f75e82678f92353163/cleverhans/utils_keras.py

   x_adv_sub = fgsm.generate(images_tensor, **fgsm_par)
File "/content/defensegan/cleverhans/attacks/fast_gradient_method.py", 
   line 50, in generate
   labels, _nb_classes = self.get_or_guess_labels(x, kwargs)
File "/content/defensegan/cleverhans/attacks/attack.py", line 278, in 
   get_or_guess_labels
   preds = self.model.get_probs(x)
File "/content/defensegan/cleverhans/utils_keras.py", line 196, in 
   get_probs
  :return: Names of all the layers kept by Keras
File "/content/defensegan/cleverhans/utils_keras.py", line 130, in 
  _get_softmax_name
   def _get_abstract_layer_name(self):
AttributeError: 'Conv2D' object has no attribute 'get_config'