[1.1.X] Fixed #12688 -- Removed typo in manager docs. Thanks, orokusaki for...

[1.1.X] Fixed #12688 -- Removed typo in manager docs. Thanks, orokusaki for the report and timo for the patch. 

r12485 from trunk.


git-svn-id: http://code.djangoproject.com/svn/django/branches/releases/1.1.X@13079 bcc190cf-cafb-0310-a4f2-bffc1f526a37