Fixed #13328 -- Ensured that querysets on models with callable defaults can be...

Fixed #13328 -- Ensured that querysets on models with callable defaults can be pickled. No, really this time. Thanks to Alex for his help brainstorming the solution.

git-svn-id: http://code.djangoproject.com/svn/django/trunk@13013 bcc190cf-cafb-0310-a4f2-bffc1f526a37