message: fix http upload
diff: @@ -92,12 +92,12 @@ export default class HttpUploadService {
  return xhr;
  },
  - success: function() {
  + success: () => {
  this.pluginAPI.Log.debug('file successful uploaded');
  resolve();
  },
  - error: function() {
  + error: () => {
  this.pluginAPI.Log.warn('error while uploading file to ' + putUrl);
  reject();
  