Don't run dhcpcd in containers

nixos/modules/virtualisation/containers.nix

@@ -156,6 +156,7 @@ in
                       { boot.isContainer = true;
                         security.initialRootPassword = mkDefault "!";
                         networking.hostName = mkDefault name;
+                        networking.useDHCP = false;
                         imports = [ ./container-login.nix ];
                       };
                     in [ extraConfig config.config ];