Removed Python 2 comment in ValidationError.
@@ -102,8 +102,6 @@ class ValidationError(Exception):
list or dictionary can be an actual `list` or `dict` or an instance
of ValidationError with its `error_list` or `error_dict` attribute set.
"""
-
- # PY2 can't pickle naive exception: http://bugs.python.org/issue1692335.
super().__init__(message, code, params)
if isinstance(message, ValidationError):
