Remove not used code in FrameGemerator

Two variables are not used after assignment

Author: natravedrova

site/en/tutorials/load_data/video.ipynb

@@ -741,8 +741,6 @@
         "\n",
         "    random.shuffle(pairs)\n",
         "\n",
-        "    shuffled_video_paths, shuffled_classes = zip(*pairs)\n",
-        "\n",
         "    for path, name in pairs:\n",
         "      video_frames = frames_from_video_file(path, self.n_frames) \n",
         "      label = self.class_ids_for_name[name] # Encode labels\n",