dns/openmdns: fix interface selection in rc.d

- Don't append default interface when /etc/rc.conf has mdnsd_flags
- Switch to lo0 as a more predictable (but less useful) default interface

PR:		214366
Submitted by:	Dave Cottlehuber <dch@skunkwerks.at>

dns/openmdns/Makefile

@@ -3,6 +3,7 @@
 PORTNAME=	openmdns
 DISTVERSION=	0.6-11
 DISTVERSIONSUFFIX=	-g2008828
+PORTREVISION=	1
 CATEGORIES=	dns
 
 MAINTAINER=	jbeich@FreeBSD.org

dns/openmdns/files/mdnsd.in

@@ -13,10 +13,10 @@ name="mdnsd"
 desc="%%COMMENT%%"
 rcvar="${name}_enable"
 command="%%PREFIX%%/sbin/${name}"
-command_args="em0"
 extra_commands="reload"
 
 : ${mdnsd_enable:="NO"}
+: ${mdnsd_flags:="lo0"}
 
 load_rc_config $name
 run_rc_command "$1"