Only disable ctrl-alt-del once

src/freedombone-utils-setup

@@ -500,7 +500,10 @@ function set_sticky_bits {
 }
 
 function disable_ctrl_alt_del {
-    ln -sf /dev/null /etc/systemd/system/ctrl-alt-del.target
+    ctrl_alt_del=$(ls -l /etc/systemd/system/ctrl-alt-del.target)
+    if [[ "$ctrl_alt_del" !=  *'/dev/null' ]]; then
+        ln -sf /dev/null /etc/systemd/system/ctrl-alt-del.target
+    fi
 }
 
 function lockdown_permissions {