xkblayout-state: drop unneeded qt4 dep

pkgs/applications/misc/xkblayout-state/default.nix

···
-{ lib, stdenv, fetchFromGitHub, qt4 }:
+{ lib, stdenv, fetchFromGitHub, libX11 }:
 
 stdenv.mkDerivation rec {
   pname = "xkblayout-state";
···
     sha256 = "sha256-diorqwDEBdzcBteKvhRisQaY3bx5seaOaWSaPwBkWDo=";
   };
 
-  buildInputs = [ qt4 ];
+  buildInputs = [ libX11 ];
 
   installPhase = ''
     mkdir -p $out/bin