Workaround an issue with kqueue support.

OpenLDAP does slapd_daemon_init() which will initialize kqueue(), but then
calls lutil_detach() which will fork(), and the fork() would invalidate the
kqueue descriptor in the child process.

Completely solving this would require some intrusive changes so workaround
this for now by calling rfork() without RFFDG and reorder file descriptor
closure order.

While I'm there also refrain from stopping slapd when deinstalling.