libyaml: actually use 0.2.2

The archive that was used turned out to be incorrect.
https://github.com/yaml/pyyaml/issues/320

By now a correct tarball has been uploaded but in order
to prevent issues like these we fetch now instead from GitHub.

pkgs/development/libraries/libyaml/default.nix

@@ -1,14 +1,21 @@
-{ stdenv, fetchurl }:
+{ stdenv
+, fetchFromGitHub
+, autoreconfHook
+}:
 
 stdenv.mkDerivation rec {
   pname = "libyaml";
   version = "0.2.2";
 
-  src = fetchurl {
-    url = "https://pyyaml.org/download/libyaml/yaml-${version}.tar.gz";
-    sha256 = "1karpcfgacgppa82wm2drcfn2kb6q2wqfykf5nrhy20sci2i2a3q";
+  src = fetchFromGitHub {
+    owner = "yaml";
+    repo = "libyaml";
+    rev = version;
+    sha256 = "0839nqcmxjzfgjn39j7740pnlsgmvngpkamiw1lfy1qlcqyc3r4v";
   };
 
+  nativeBuildInputs = [ autoreconfHook ];
+
   meta = with stdenv.lib; {
     homepage = https://pyyaml.org/;
     description = "A YAML 1.1 parser and emitter written in C";