Comment 5 for bug 1957933

Originated from this issue below.
https://bugs.launchpad.net/python-swiftclient/+bug/1506383

This problem is marked as commited but it is not working properly.

warnings.warn(
                'Providing attr without filter_value to get_urls() is '
                'deprecated as of the 1.7.0 release and may be removed in the '
                '2.0.0 release. Either both should be provided or neither '
                'should be provided.')

The commit forces put literal 'attr' to filter_kwarg though I think attr is attribute to filter.
Thus, literal 'attr' should be 'region_name' and corresponding filter value should be provided in the kwarg dict.