realize l2 bridge utilization in vhosts

hardware-configuration.nix

@@ -39,7 +39,9 @@
       RUN+="/bin/sh -c 'modprobe ahci; echo 0000:08:00.0 > /sys/bus/pci/drivers_probe'"
   '';
 
-  boot.kernel.sysctl."net.ipv4.conf.all.forwarding" = true;
+  boot.kernel.sysctl = {
+    "net.ipv4.conf.all.forwarding" = true;
+  };
 
   swapDevices =
     [ { device = "/dev/disk/by-uuid/7e34cdc3-bd48-435a-8ea2-e1fe43926262"; }