host: Fix libvirt's iptables conumdrum

overlays/simple.nix

@@ -38,4 +38,10 @@ in {
       parallel-n64
     ];
   });
+
+  libvirt = prev.libvirt.override {
+    # NOTE: This to prevent libvirt from using iptables and loading
+    #       ip_tables and the likes
+    iptables = prev.iptables-nftables-compat;
+  };
 }