[1.2.X] Fixed #13702 -- Made sure to actually fall back to the l10n format...

[1.2.X] Fixed #13702 -- Made sure to actually fall back to the l10n format strings provided in the settings, when disabled.

Backport from trunk (r13770).

git-svn-id: http://code.djangoproject.com/svn/django/branches/releases/1.2.X@13771 bcc190cf-cafb-0310-a4f2-bffc1f526a37