rc.d/ntp: Ensure ntpd.leap-seconds.list is readable by ntpd

When a use sets umask in login.conf(5) to 027 or 077 a subsequently
fetched /var/db/ntpd.leap-seconds.list will inherit the permissions
allowed by the umask, resulting in a file that may not be readable
ntpd running under the ntp account. This patch adds a umask command
to preempt the umask in login.conf(5) prior to fetching a new copy
of the leap-seconds file.

PR:		261298
Reported by:	Martin Waschbusch <[email protected]>

(cherry picked from commit c680643)

libexec/rc/rc.d/ntpd

@@ -221,6 +221,8 @@ ntpd_fetch_leapfile() {
 	if ntpd_needfetch_leapfile ; then
 		for url in $ntp_leapfile_sources ; do
 			$verbose fetching $url
+			# Circumvent umask 027 and 077 in login.conf(5)
+			umask 022
 			fetch $ntp_leapfile_fetch_opts -o $_ntp_tmp_leapfile $url && break
 		done
 		ntp_ver_no_tmp=$(get_ntp_leapfile_ver $_ntp_tmp_leapfile)