misc pkgs: Manual fixup pkgconfig nativeBuildInputs after sed

Importantly, this included regenerating pkgs/servers/x11/xorg, to
clobber the old sed.

pkgs/development/libraries/fflas-ffpack/default.nix

@@ -9,9 +9,8 @@ stdenv.mkDerivation rec {
     rev = "v${version}";
     sha256 = "0k1f4pb7azrm6ajncvg7vni7ixfmn6fssd5ld4xddbi6jqbsf9rd";
   };
-  nativeBuildInputs = [ autoreconfHook ];
+  nativeBuildInputs = [ autoreconfHook pkgconfig ];
   buildInputs = [ givaro (liblapack.override {shared = true;}) openblas];
-  nativeBuildInputs = [pkgconfig];
   configureFlags = "--with-blas-libs=-lopenblas --with-lapack-libs=-llapack";
   meta = {
     inherit version;