Fixed #17197 -- Prevented a locale leakage from an i18n test causing...

Fixed #17197 -- Prevented a locale leakage from an i18n test causing collateral failures in the rest of the test suite. Thanks to Florian Apolloner for the report and patch.

git-svn-id: http://code.djangoproject.com/svn/django/trunk@17080 bcc190cf-cafb-0310-a4f2-bffc1f526a37