[1.2.X] Fixed #13798 -- Added connection argument to the connection_created...

[1.2.X] Fixed #13798 -- Added connection argument to the connection_created signal. Thanks to liangent for the report, and Alex Gaynor for the patch.

Backport of r13672 from trunk.

git-svn-id: http://code.djangoproject.com/svn/django/branches/releases/1.2.X@13674 bcc190cf-cafb-0310-a4f2-bffc1f526a37