errors: default formdef_class is None now (#49444)

tests/admin_pages/test_workflow.py

@@ -1811,6 +1811,7 @@ def test_workflows_wscall_status_error(pub):
     error = pub.loggederror_class.select()[0]
     assert error.tech_id == '%s-reference-to-invalid-status-in-workflow-foo-status-baz-item-webservice' % workflow.id
     assert error.formdef_id is None
+    assert error.formdef_class is None
     assert error.workflow_id == workflow.id
     assert error.summary == 'reference to invalid status in workflow foo, status baz, item Webservice'
     assert error.occurences_count == 5

wcs/logged_errors.py

@@ -28,7 +28,7 @@ class LoggedError(object):
     id = None
     tech_id = None
     summary = None
-    formdef_class = 'FormDef'
+    formdef_class = None
     formdata_id = None
     formdef_id = None
     workflow_id = None