Fixed a missing import in mysql backend. Thanks for pointing it out, mattmcc.

git-svn-id: http://code.djangoproject.com/svn/django/trunk@6244 bcc190cf-cafb-0310-a4f2-bffc1f526a37

django/db/backends/mysql/base.py

@@ -25,6 +25,7 @@ import types
 import re
 
 # Raise exceptions for database warnings if DEBUG is on
+from django.conf import settings
 if settings.DEBUG:
     from warnings import filterwarnings
     filterwarnings("error", category=Database.Warning)