[1.0.X] Fixed #9555: respect the `feed_url` feed parameter. Thanks, sedden....

[1.0.X] Fixed #9555: respect the `feed_url` feed parameter. Thanks, sedden. Backport of r10432 from trunk.

git-svn-id: http://code.djangoproject.com/svn/django/branches/releases/1.0.X@10433 bcc190cf-cafb-0310-a4f2-bffc1f526a37