ghostunnel: use default SDK on Darwin (14.4)

pkgs/by-name/gh/ghostunnel/package.nix

@@ -5,8 +5,6 @@
   lib,
   nixosTests,
   ghostunnel,
-  apple-sdk_12,
-  darwinMinVersionHook,
   writeScript,
   runtimeShell,
 }:
@@ -26,11 +24,6 @@ buildGoModule rec {
 
   deleteVendor = true;
 
-  buildInputs = lib.optionals stdenv.hostPlatform.isDarwin [
-    apple-sdk_12
-    (darwinMinVersionHook "12.0")
-  ];
-
   # These tests don't exist for Linux, and on Darwin they attempt to use the macOS Keychain
   # which doesn't work from a nix build. Presumably other platform implementations of the
   # certstore would have similar issues, so it probably makes sense to skip them in