net/zebra: Update MASTER_SITES, deprecate and set expiration date to …

…2021-12-31

Remove dead mirrors, Zebra's last release was back in 2005 and is
abandoned upstream

Reference: https://www.gnu.org/software/zebra/

Approved by:	bdrewery (port maintainer), arrowd (mentor)
Differential Revision:	https://reviews.freebsd.org/D32469

net/zebra/Makefile

@@ -4,16 +4,17 @@ PORTNAME=	zebra
 PORTVERSION=	0.95a
 PORTREVISION=	10
 CATEGORIES=	net
-MASTER_SITES=	ftp://ftp.pop-pr.rnp.br/pub/GNU/ftp.zebra.org/zebra/ \
-		ftp://ftp.ripe.net/mirrors/sites/ftp.zebra.org/pub/zebra/ \
-		http://ftp.sunet.se/pub/network/zebra/
+MASTER_SITES=	ftp://ftp.ripe.net/mirrors/sites/ftp.zebra.org/pub/zebra/
 
 MAINTAINER=	bdrewery@FreeBSD.org
 COMMENT=	Free RIPv1, RIPv2, OSPFv2, BGP4 route software (server/reflector)
 
 LICENSE=	GPLv2 LGPL21
 LICENSE_COMB=	multi
 
+DEPRECATED=	Abandoned upstream, last release in 2005. Consider migrating to net/frr7 or net/bird2
+EXPIRATION_DATE=2021-12-31
+
 CONFLICTS=	openbgpd-[0-9]* quagga-[0-9]* quagga-re-[0-9]* openospfd-[0-9]*
 
 SUB_FILES=	pkg-message zebractl