Metaproxy already did this for normal stop (SIGTERM). This ensure
that children processes spawned by modules are removed upon
termination of graceful stop too.
mp::Package pack;
pack.router(*routerp).move();
yaz_log(YLOG_LOG, "metaproxy stop"); /* only for graceful stop */
mp::Package pack;
pack.router(*routerp).move();
yaz_log(YLOG_LOG, "metaproxy stop"); /* only for graceful stop */
+ kill(-process_group, SIGTERM); /* kill all children processes as well */