module(wp): link domain to conf

modules/web-apps/wordpress/module.nix

@@ -4,6 +4,7 @@ let
   cfg = config.services.wordpress;
   callPackage = pkgs.callPackage;
   appConfig = (import ./default-app-config.nix).extend (self: super: {
+    inherit (cfg) domain;
     wpConfig = super.wpConfig.extend (self: super: {
       secrets = cfg.wpConfigSecrets;
     });