Fixed #10868 -- Stopped restoring database connections after the tests'...

Fixed #10868 -- Stopped restoring database connections after the tests' execution in order to prevent the production database from being exposed to potential threads that would still be running. Also did a bit of PEP8-cleaning while I was in the area. Many thanks to ovidiu for the report and to Anssi Kääriäinen for thoroughly investigating this issue.

git-svn-id: http://code.djangoproject.com/svn/django/trunk@17411 bcc190cf-cafb-0310-a4f2-bffc1f526a37