make configuration.nix host agnostic and add nix-conv

configuration.nix

@@ -36,11 +36,6 @@
 
   };
 
-  networking.hostName = "nix-desk"; # Define your hostname.
-  networking.networkmanager.enable = true;  # Easiest to use and most distros use this by default.
-  # required for ZFS
-  networking.hostId = "00000001";
-
   # Set your time zone.
   time.timeZone = "Europe/Berlin";
 
@@ -105,10 +100,6 @@
     htop
     ];
 
-  # allow specific users to affect system configuration
-  users.groups.nixos-admins = {};
-  users.users.root.extraGroups = [ "nixos-admins" ];
-
   # Some programs need SUID wrappers, can be configured further or are
   # started in user sessions.
   # programs.mtr.enable = true;