Fix evil typo (multicast_hosts -> multicast_host).

src/etc/rc.d/rc.subr

@@ -1,4 +1,4 @@
-#	$OpenBSD: rc.subr,v 1.74 2014/07/12 15:32:43 robert Exp $
+#	$OpenBSD: rc.subr,v 1.75 2014/07/30 13:18:59 ajacoutot Exp $
 #
 # Copyright (c) 2010, 2011, 2014 Antoine Jacoutot <ajacoutot@openbsd.org>
 # Copyright (c) 2010, 2011 Ingo Schwarze <schwarze@openbsd.org>
@@ -119,7 +119,7 @@ _rc_parse_conf() {
 	local _rcconf_local="/etc/rc.conf.local"
 	set -A _allowed_keys -- \
 		spamd_black pf ipsec check_quotas accounting \
-		multicast_hosts multicast_router amd_master \
+		multicast_host multicast_router amd_master \
 		pf_rules ipsec_rules shlib_dirs pkg_scripts \
 		nfs_server