nixos/xautolock: always run systemctl of the currently running systemd

Changed files
+1 -1
nixos
modules
services
+1 -1
nixos/modules/services/x11/xautolock.nix
···
killer = mkOption {
default = null; # default according to `man xautolock` is none
-
example = "${pkgs.systemd}/bin/systemctl suspend";
+
example = "/run/current-system/systemd/bin/systemctl suspend";
type = types.nullOr types.str;
description = ''