fix prepare_nftables

lib/functions.sh

@@ -100,7 +100,7 @@ function disable_all_signals {
 function prepare_nftables() {
     local PREFIX="miaou:nftables"
 
-    if [[ ! -f /etc/nftables.rules.d/firewall.table ]]; then
+    if ! diff -q "$MIAOU_BASEDIR/templates/hardened/nftables.conf" /etc/nftables.conf 2>/dev/null; then
         echo "installing nftables ..."
         sudo apt install -y nftables
         sudo cp -f "$MIAOU_BASEDIR/templates/hardened/nftables.conf" /etc/