Fixed #16568 -- Added RequireDebugFalse filter to prevent sending 500 error emails when DEBUG is True in projects with no explicit LOGGING setting. Thanks to Andreas Pelme for report and patch.

git-svn-id: http://code.djangoproject.com/svn/django/trunk@16840 bcc190cf-cafb-0310-a4f2-bffc1f526a37