nixos/mosh: use mkEnableOption

nixos/modules/programs/mosh.nix

@@ -1,7 +1,5 @@
 { config, lib, pkgs, ... }:
 
-with lib;
-
 let
 
   cfg  = config.programs.mosh;
@@ -9,28 +7,22 @@ let
 in
 {
   options.programs.mosh = {
-    enable = mkOption {
-      description = lib.mdDoc ''
-        Whether to enable mosh. Note, this will open ports in your firewall!
-      '';
-      default = false;
-      type = lib.types.bool;
-    };
-    withUtempter = mkOption {
+    enable = lib.mkEnableOption "mosh";
+    withUtempter = lib.mkEnableOption "" // {
       description = lib.mdDoc ''
         Whether to enable libutempter for mosh.
+
         This is required so that mosh can write to /var/run/utmp (which can be queried with `who` to display currently connected user sessions).
         Note, this will add a guid wrapper for the group utmp!
       '';
       default = true;
-      type = lib.types.bool;
     };
   };
 
-  config = mkIf cfg.enable {
-    environment.systemPackages = with pkgs; [ mosh ];
+  config = lib.mkIf cfg.enable {
+    environment.systemPackages = [ pkgs.mosh ];
     networking.firewall.allowedUDPPortRanges = [ { from = 60000; to = 61000; } ];
-    security.wrappers = mkIf cfg.withUtempter {
+    security.wrappers = lib.mkIf cfg.withUtempter {
       utempter = {
         source = "${pkgs.libutempter}/lib/utempter/utempter";
         owner = "root";