Fixed #12452 -- Ensured that all connections are closed when a request is...

Fixed #12452 -- Ensured that all connections are closed when a request is finished. Thanks to samuel@lefora.com for the report and fix.

git-svn-id: http://code.djangoproject.com/svn/django/trunk@12008 bcc190cf-cafb-0310-a4f2-bffc1f526a37