* Merged the stdenv branch

(https://svn.nixos.org/repos/nix/nixpkgs/branches/stdenv-updates
  -r10966:12061).

svn path=/nixpkgs/trunk/; revision=12073

pkgs/development/libraries/gnutls/default.nix

@@ -19,7 +19,7 @@ stdenv.mkDerivation rec {
   '';
 
   buildInputs = [zlib lzo libgcrypt]
-    ++ (if guileBindings then [guile] else []);
+    ++ stdenv.optional guileBindings guile;
 
   doCheck = true;