message: http_loader: use _curl_wrapper for sync dl
diff: @@ -114,8 +114,7 @@ bool HttpLoader::do_upload(const std::shared_ptr<UploadItem> &item,
  bool HttpLoader::download_text_sync(const std::string &url, std::string &content)
  {
  - CurlWrapper curl_wrapper;
  - bool success = curl_wrapper.download_text(url, content);
  + bool success = _curl_wrapper->download_text(url, content);
  return success;
  }
  