* @param form the action form (validated but not used for configuration)
     * @return HTML response redirecting to the maintenance page
     */
    @Execute
    @Secured({ ROLE })
    public HtmlResponse reloadDocIndex(final ActionForm form) {
        validate(form, messages -> {}, this::asIndexHtml);
        verifyToken(this::asIndexHtml);
        searchEngineClient.flushConfigFiles(() -> {