[1.2.X] Fixed #15592 -- corrected an missing backtick in the syndication docs....

[1.2.X] Fixed #15592 -- corrected an missing backtick in the syndication docs. Thanks to bradley.ayers for the report and patch.

Backport of [15793] from trunk.

git-svn-id: http://code.djangoproject.com/svn/django/branches/releases/1.2.X@15794 bcc190cf-cafb-0310-a4f2-bffc1f526a37