net/ntp: sync with upstream

Taken from: FreeBSD

net/ntp/Makefile

@@ -1,5 +1,6 @@
 PORTNAME=	ntp
 PORTVERSION=	4.2.8p18
+PORTREVISION=	1
 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 +1,18 @@
+--- ntpd/ntp_proto.c.orig	2024-05-07 04:21:28.000000000 -0700
++++ ntpd/ntp_proto.c	2024-12-23 14:40:06.218503000 -0800
+@@ -471,6 +471,7 @@
+ 		return;
+ 	}
+ 
++#if 0
+ 	/* [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)
+@@ -479,6 +480,7 @@
+ 			return;
+ 		}
+ 	}
++#endif
+ 
+ 	 /*
+ 	 * In unicast modes the dance is much more intricate. It is