Restrict others permission

Author: forsyth2

tests/integration/image_checker.py

@@ -184,7 +184,7 @@ def _check_mismatched_images(
 
     # Make diff_dir readable
     if os.path.exists(parameters.diff_dir):
-        _chmod_recursive(parameters.diff_dir, 0o755)
+        _chmod_recursive(parameters.diff_dir, 0o754)
     else:
         # diff_dir won't exist if all the expected images are missing
         # That is, if we're in this case, we expect the following: