grafana: fix error undefing var config and firewall config

systems/grafana.noc.eh22.intern.nix

@@ -1,10 +1,13 @@
 {
   pkgs,
+  config,
   ...
 }:
 {
   imports = [];
 
+  # configure static IP address
+  networking.useDHCP = false;
   systemd.network = {
     enable = true;
     networks = {
@@ -16,6 +19,8 @@
     };
   };
   
+  networking.firewall.allowedTCPPorts = [ 80 ];
+
   services.grafana = {
     enable = true;
     security.admin_password = "$__file{${sops.secrets.vms.grafana.admin_password.path}}";
@@ -32,6 +37,8 @@
     };
   };
 
+
+
   sops = {
     defaultSopsFile = ../secrets/passwords.yaml;
     "vms"."grafana"."admin_password" = {