add note that on NetBSD, the server works only when run in the foreground
add note that on NetBSD, the server works only
when run in the foreground

pecharmin/bind9,each/bind9-collab,pecharmin/bind9,pecharmin/bind9,each/bind9-collab,each/bind9-collab,each/bind9-collab,pecharmin/bind9,pecharmin/bind9,pecharmin/bind9,each/bind9-collab,each/bind9-collab