Fixed #8053 -- Corrected a bug with reset and m2m intermediate tables. Thanks...

Fixed #8053 -- Corrected a bug with reset and m2m intermediate tables. Thanks to d00gs for the report and fix.

git-svn-id: http://code.djangoproject.com/svn/django/trunk@8157 bcc190cf-cafb-0310-a4f2-bffc1f526a37