Fixing weights_path reference

DeOldify_colab.ipynb

@@ -524,7 +524,7 @@
     "#though you may also find that certiain images will actually render better at lower numbers.  \n",
     "#This tends to be the case with the oldest photos.\n",
     "render_factor=42\n",
-    "filters = [Colorizer(gpu=0, weights_path=colorizer_path)]\n",
+    "filters = [Colorizer(gpu=0, weights_path=weights_path)]\n",
     "vis = ModelImageVisualizer(filters, render_factor=render_factor, results_dir='result_images')"
    ]
   },