Made a minor tweak to a doctoring in django/forms.forms.py that was…

… missed in r17452. Thanks to Claude Paroz for the tip.

git-svn-id: http://code.djangoproject.com/svn/django/trunk@17453 bcc190cf-cafb-0310-a4f2-bffc1f526a37

django/forms/forms.py

@@ -544,7 +544,7 @@ def _auto_id(self):
 
     def _id_for_label(self):
         """
-        Wrapper around the field widget's `id_for_label` class method.
+        Wrapper around the field widget's `id_for_label` method.
         Useful, for example, for focusing on this field regardless of whether
         it has a single widget or a MutiWidget.
         """