chg: use default server instead of hostname

configuration.nix

@@ -59,7 +59,7 @@
   # Nginx webserver configuration
   services.nginx = {
     enable = true;
-    virtualHosts."levitest" = {
+    virtualHosts."default_server" = {
       root = "/var/www/default";
     };
   };
@@ -122,7 +122,7 @@
   # List packages installed in system profile. To search, run:
   # $ nix search wget
   environment.systemPackages = with pkgs; [
-    wget vim git htop tmux nginx
+    wget vim git htop tmux
   ];
 
 }