misc: makes sure category id works as strings in backoffice

extra/modules/forms_ui.py

@@ -92,7 +92,7 @@ class FormsDirectory(AccessControlled, Directory):
         cats = Category.select(order_by = 'name')
         lists = []
         for c in cats:
-            t = [x for x in l if x.category_id == c.id]
+            t = [x for x in l if str(x.category_id) == str(c.id)]
             if t:
                 lists.append((c.name, t))
         t = [x for x in l if x.category_id is None]