Fixed a broken translation string in the flatpages' forms module.

git-svn-id: http://code.djangoproject.com/svn/django/trunk@17249 bcc190cf-cafb-0310-a4f2-bffc1f526a37

django/contrib/flatpages/forms.py

@@ -24,7 +24,7 @@ class FlatpageForm(forms.ModelForm):
             for site in sites:
                 if same_url.filter(sites=site).exists():
                     raise forms.ValidationError(
-                        _('Flatpage with url %s already exists for site %s'
-                          % (url, site)))
+                        _('Flatpage with url %(url)s already exists for site %(site)s' %
+                          {'url': url, 'site': site}))
 
         return super(FlatpageForm, self).clean()