message: [Dashboard bug] Fix merged filter param name
  front-end merge time filter params, and update query with param name 'extra_filters'
diff: @@ -121,7 +121,7 @@ class Dashboard extends React.PureComponent {
  getFormDataExtra(slice) {
  const formDataExtra = Object.assign({}, slice.formData);
  const extraFilters = this.effectiveExtraFilters(slice.slice_id);
  - formDataExtra.filters = formDataExtra.filters.concat(extraFilters);
  + formDataExtra.extra_filters = formDataExtra.filters.concat(extraFilters);
  return formDataExtra;
  }
  