message: convert raw bytes to bytes object, not str object
diff: @@ -75,7 +75,7 @@ uint64_t current_code_() { return get_validate_ctx().code.value; }
  mp_obj_t read_message_() {
  auto& bs = get_validate_ctx().msg.data;
  - return mp_obj_new_str(bs.data(), bs.size());
  + return mp_obj_new_bytes((unsigned char *)bs.data(), bs.size());
  }
  void require_scope_(uint64_t account) {
  