Fixes #7845: Removed a piece of stale code that was causing ./manage.py reset...

Fixes #7845: Removed a piece of stale code that was causing ./manage.py reset to fail with apps that don't have any models. Thanks to miracle2k for the report and patch.

git-svn-id: http://code.djangoproject.com/svn/django/trunk@8401 bcc190cf-cafb-0310-a4f2-bffc1f526a37