Add $sshd and $sshd_flags for use by both usr.bin/sshd and pkgsrc/security/{open,}ssh

As a precedent, note the presence of $gated, even though we do not distribute
gated outside of pkgsrc.

etc/rc.conf

@@ -1,4 +1,4 @@
-#	$NetBSD: rc.conf,v 1.90 2000/07/22 01:09:44 lukem Exp $
+#	$NetBSD: rc.conf,v 1.91 2000/07/31 20:47:41 jwise Exp $
 #
 # see rc.conf(5) for more information.
 #
@@ -111,6 +111,7 @@ ntpd=NO			ntpd_flags=""
 sendmail=NO		sendmail_flags="-bd -q30m"
 postfix=NO
 lpd=NO			lpd_flags="-s"		# -s "secure" unix domain only
+sshd=NO			sshd_flags=""
 
 # Routing daemons.
 #