gnome3.webkitgtk: 2.20.0 -> 2.20.1 (#38824)

Semi-automatic update generated by https://github.com/ryantm/nixpkgs-update tools.

This update was made based on information from https://repology.org/metapackage/webkitgtk/versions.

These checks were done:

- built on NixOS
- ran ‘/nix/store/4iba6cp8lj5v53lzk6j3djrnf790byj4-webkitgtk-2.20.1/bin/WebKitWebDriver -h’ got 0 exit code
- ran ‘/nix/store/4iba6cp8lj5v53lzk6j3djrnf790byj4-webkitgtk-2.20.1/bin/WebKitWebDriver --help’ got 0 exit code
- found 2.20.1 with grep in /nix/store/4iba6cp8lj5v53lzk6j3djrnf790byj4-webkitgtk-2.20.1
- directory tree listing: https://gist.github.com/a60788ffc43ea1bedb466120462ff111

pkgs/development/libraries/webkitgtk/2.20.nix

@@ -15,7 +15,7 @@ assert stdenv.isDarwin -> !enableGtk2Plugins;
 with stdenv.lib;
 stdenv.mkDerivation rec {
   name = "webkitgtk-${version}";
-  version = "2.20.0";
+  version = "2.20.1";
 
   meta = {
     description = "Web content rendering engine, GTK+ port";
@@ -28,7 +28,7 @@ stdenv.mkDerivation rec {
 
   src = fetchurl {
     url = "http://webkitgtk.org/releases/${name}.tar.xz";
-    sha256 = "0g0an3pc2yz13gzpaysfgch2yp510gw1qcpk0xr8m6mx43vl1xjp";
+    sha256 = "0nc9dj05dbk31ciip08b3rdsfja7ckc5mgagrj030fafza2k5r23";
   };
 
   patches = optionals stdenv.isDarwin [