If running with nbproc > 1, haproxy spawns several processes and writes their
pids to $pidfile (one pid per line).
Our check_pidfile() from rc.subr will get only first pid and use it for
stop/status/etc which is incorrect.
Do not use pidfile for that, rather use $procname to get the list of running
[If you know how to do the same with pidfile, please tell me.]