json_form: fix str/bytes confusion

bt5/erp5_json_form/ModuleComponentTemplateItem/portal_components/document.erp5.JSONForm.py

@@ -82,7 +82,7 @@ class JSONForm(JSONType, TextDocument):
       if list_error:
         validator = jsonschema.validators.validator_for(defined_schema)(defined_schema, format_checker=jsonschema.FormatChecker())
         return {
-          defined_schema["$id"].decode(): [
+          defined_schema["$id"]: [
             ("Validation Error", x.message) for x in sorted(validator.iter_errors(json_data), key=lambda e: e.path)
           ]
         }