go1.6: patch test to work with recent tzdata

pkgs/development/compilers/go/1.6.nix

@@ -113,6 +113,13 @@ stdenv.mkDerivation rec {
   patches = [
     ./remove-tools-1.5.patch
     ./creds-test.patch
+
+    # This test checks for the wrong thing with recent tzdata. It's been fixed in master but the patch
+    # actually works on old versions too.
+    (fetchpatch {
+      url    = "https://github.com/golang/go/commit/91563ced5897faf729a34be7081568efcfedda31.patch";
+      sha256 = "1ny5l3f8a9dpjjrnjnsplb66308a0x13sa0wwr4j6yrkc8j4qxqi";
+    })
   ];
 
   GOOS = if stdenv.isDarwin then "darwin" else "linux";