Disable and remove not required xscreensaver.

modules/desktop/files/etc/skel/.config/lxsession/LXDE/autostart

 @lxpanel --profile LXDE
 @pcmanfm --desktop --profile LXDE
-@xscreensaver -no-splash

modules/desktop/manifests/init.pp

@@ -28,6 +28,10 @@ class desktop {
 		require => Package['lxde'],
 	}
 
+	package { 'xscreensaver':
+		ensure => absent,
+	}
+
 	$packages = [
 		'pcmanfm',
 		'iceweasel',