Fix after cherry-picking for 0.4.2

fmassa · fmassa · commit 600a184aa9b3 · 2019-10-31T16:17:10.000+01:00
diff --git a/test/test_datasets_video_utils.py b/test/test_datasets_video_utils.py
@@ -1,3 +1,4 @@
+import sys
 import contextlib
 import os
 import torch
