Cleanup 'admin' slug error message

wiki/forms.py

@@ -251,7 +251,7 @@ class CreateForm(forms.Form, SpamProtectionMixin):
         if slug.startswith("_"):
             raise forms.ValidationError(_(u'A slug may not begin with an underscore.'))
         if slug == 'admin':
-            raise forms.ValidationError(_(u'Sorry, you cannot use admin as a slug !'))            
+            raise forms.ValidationError(_(u"'admin' is not a permitted slug name."))
         
         if settings.URL_CASE_SENSITIVE:
             already_existing_slug = models.URLPath.objects.filter(slug=slug, parent=self.urlpath_parent)