Fix scope issue in python 2

keras_transformer/transformer.py

@@ -464,7 +464,7 @@ def decode(model,
             if top_k == 1:
                 last_token = predicts[i][-1].argmax(axis=-1)
             else:
-                probs = [(prob, i) for i, prob in enumerate(predicts[i][-1])]
+                probs = [(prob, j) for j, prob in enumerate(predicts[i][-1])]
                 probs.sort(reverse=True)
                 probs = probs[:top_k]
                 indices, probs = list(map(lambda x: x[1], probs)), list(map(lambda x: x[0], probs))