adapt to modern ntp.conf file used by ntpsec

modules/conf_ntp.sh

@@ -39,7 +39,11 @@ conf_ntp()
     prnt I "Installing NTP configuration file..."
     local dest="${conf_file}.work"
     backup_dist "$conf_file"
-    install_file ntp.conf "$dest"
+    if [[ -s $NTP_SERV ]]; then
+	install_file ${NTP_SERV}.conf "$dest"
+    else
+	install_file ntp.conf "$dest"
+    fi
     tag_file "$dest"
     local line=""
     for srv in $NTP_SERVERS; do