Error for entities without langcode field

Line 92 of manage_display_fix_title.module (in quickedit_preprocess_entity_page_title() ) reads

  $variables['attributes']['data-quickedit-field-id'] = $entity->getEntityTypeId() . '/' . $entity->id() . '/' . $label_field . '/' . $entity->get('langcode')->value . '/' . $variables['view_mode'];

But Commerce Order doesn't have langcode (and I suppose there may be other entities that don't have it - it's quite legal), which results in fatal error.