fix: clone workflow custom fields correctly

apps/wf/views.py

@@ -161,7 +161,7 @@ class WorkflowViewSet(CustomModelViewSet):
             cf.workflow = wf_new
             for f in CustomField._meta.fields:
                 if f.name not in ['workflow', 'create_time', 'update_time', 'id']:
-                    setattr(sta, f.name, getattr(s, f.name))
+                    setattr(cf, f.name, getattr(c, f.name))
             cf.save()
         for t in Transition.objects.filter(workflow=wf):
             tr = Transition()