Fix ATS does not honor proxy.config.body_factory.response_max_size

Author: shinya1020

proxy/http/HttpTransact.cc

@@ -7979,7 +7979,7 @@ HttpTransact::build_error_response(State *s, HTTPStatus status_code, const char
   int64_t len;
   char *new_msg;
 
-  new_msg = body_factory->fabricate_with_old_api(error_body_type, s, 8192, &len, body_language, sizeof(body_language), body_type,
+  new_msg = body_factory->fabricate_with_old_api(error_body_type, s, s->http_config_param->body_factory_response_max_size, &len, body_language, sizeof(body_language), body_type,
                                                  sizeof(body_type), s->internal_msg_buffer_size,
                                                  s->internal_msg_buffer_size ? s->internal_msg_buffer : nullptr);