authentication-views: fixed old style exception catch syntax.

rhodecode/authentication/views.py

@@ -84,7 +84,7 b' class AuthnPluginViewBase(object):'
 
         try:
             valid_data = schema.deserialize(data)
-        except colander.Invalid, e:
+        except colander.Invalid as e:
             # Display error message and display form again.
             self.request.session.flash(
                 _('Errors exist when saving plugin settings. '