fix stride if icons plugins use django2
@@ -79,7 +79,8 @@ class SectionMixin(object):
if not change:
# when adding a new element, `element_id` can not be validated for uniqueness
postfix = 0
- if not callable(getattr(form, "check_unique_element_id", True)):
+ # fix stride render if icons plugins use django >= 2
+ if 'check_unique_element_id' in dir(form):
form_ = SectionForm
else:
form_ = form
