net/ntp: Another patch to address IPv6 pool regression

43537eb9c3e5 circumvented an upstream patch which caused an IPv6
pool regression. This patch, discussed in
https://bugs.ntp.org/show_bug.cgi?id=3958, addresses another
unworkable combination of link-local local address with
non-link-local server.

Obtained from:	src c1767cf87cb6
MFH:		2025Q1

net/ntp/Makefile

@@ -1,6 +1,6 @@
 PORTNAME=	ntp
 PORTVERSION=	4.2.8p18
-PORTREVISION=	3
+PORTREVISION=	4
 CATEGORIES=	net
 MASTER_SITES=	http://www.eecis.udel.edu/~ntp/ntp_spool/ntp4/ntp-4.2/ \
 		http://archive.ntp.org/ntp4/ntp-4.2/

net/ntp/files/patch-ntpd_ntp__proto.c

@@ -0,0 +1,11 @@
+--- ntpd/ntp_proto.c.orig	2024-05-07 04:21:28.000000000 -0700
++++ ntpd/ntp_proto.c	2025-02-18 19:48:02.135233000 -0800
+@@ -474,7 +474,7 @@
+ 	/* [Bug 3851] drop pool servers which can no longer be reached. */
+ 	if (MDF_PCLNT & peer->cast_flags) {
+ 		if (   (IS_IPV6(&peer->srcadr) && !nonlocal_v6_addr_up)
+-		    || !nonlocal_v4_addr_up) {
++		    || (IS_IPV4(&peer->srcadr) && !nonlocal_v4_addr_up)) {
+ 			unpeer(peer);
+ 			return;
+ 		}