[3.6] bpo-29571: Use correct locale encoding in test_re (#149) (#153)

``local.getlocale(locale.LC_CTYPE)`` and
``locale.getpreferredencoding(False)`` may give different answers
in some cases (such as the ``en_IN`` locale).

``re.LOCALE`` uses the latter, so update the test case to match.
2 files changed