package/ntp: bump to version 4.2.8p18

diff COPYRIGHT:
    -* Copyright (c) Network Time Foundation 2011-2023                     *
    +* Copyright (c) Network Time Foundation 2011-2024                     *

Signed-off-by: Francois Perrad <francois.perrad@gadz.org>
Signed-off-by: Arnout Vandecappelle <arnout@mind.be>
(cherry picked from commit 49bd6bb638ff73eae3b486b207201382d46a6c05)
Signed-off-by: Peter Korsgaard <peter@korsgaard.com>

package/ntp/ntp.hash

@@ -1,4 +1,4 @@
-# From https://www.eecis.udel.edu/~ntp/ntp_spool/ntp4/ntp-4.2.8p17.tar.gz.sha256
-sha256  103dd272e6a66c5b8df07dce5e9a02555fcd6f1397bdfb782237328e89d3a866  ntp-4.2.8p17.tar.gz
+# From https://www.eecis.udel.edu/~ntp/ntp_spool/ntp4/ntp-4.2.8p18.tar.gz.sha256
+sha256  cf84c5f3fb1a295284942624d823fffa634144e096cfc4f9969ac98ef5f468e5  ntp-4.2.8p18.tar.gz
 # Locally computed
-sha256  06246b8c15ccc1a1873c78525c810f0802e68f383e79ee041e06d1ab9cbf80a4  COPYRIGHT
+sha256  45b6e5a0a5f0ac4afdd9e23caa2241779e4da463e4dba32a41b4dbd61577b2a3  COPYRIGHT

package/ntp/ntp.mk

@@ -6,7 +6,7 @@
 
 NTP_VERSION_MAJOR = 4.2
 NTP_VERSION_MINOR = 8
-NTP_VERSION_POINT = 17
+NTP_VERSION_POINT = 18
 NTP_VERSION = $(NTP_VERSION_MAJOR).$(NTP_VERSION_MINOR)p$(NTP_VERSION_POINT)
 NTP_SITE = https://www.eecis.udel.edu/~ntp/ntp_spool/ntp4/ntp-$(NTP_VERSION_MAJOR)
 NTP_DEPENDENCIES = host-pkgconf libevent