busybox: run sysntpd at higher priority

When a router is under load ntpd would have better chance to accurately
maintain system time.

Signed-off-by: Maxim Storchak <m.storchak@gmail.com>

package/utils/busybox/files/sysntpd

@@ -48,7 +48,7 @@ start_service() {
 	[ -z "$server" ] && return
 
 	procd_open_instance
-	procd_set_param command "$PROG" -n
+	procd_set_param command "$PROG" -n -N
 	[ "$enable_server" = "1" ] && procd_append_param command -l
 	[ -x "$HOTPLUG_SCRIPT" ] && procd_append_param command -S "$HOTPLUG_SCRIPT"
 	for peer in $server; do