Fixed #14164 -- Ensure that sitemap priorities aren't rendered with localized...

Fixed #14164 -- Ensure that sitemap priorities aren't rendered with localized numerical formats. Thanks to dokterbob for the report, and vung for the draft patch.

git-svn-id: http://code.djangoproject.com/svn/django/trunk@13644 bcc190cf-cafb-0310-a4f2-bffc1f526a37