Update upstream revision

upstream/default.nix

@@ -26,8 +26,8 @@ let
 
       src = nixpkgs.fetchgit {
         url = "https://git.sr.ht/~ehmry/genode";
-        rev = "e22d21e49f298ed9bba2f05eff0ab3390674040a";
-        sha256 = "0i7a18rxzjb1nv42039dbjwvf4bnsi2rl8zcs8amj6kbxfyrdk9z";
+        rev = "d28abff776f94dc876662eb7dcdf5a6e81d26cc8";
+        sha256 = "1ibw27s352c2si22y209q17api8gaqv7qsh70vh4wk9bfv1kgchx";
         fetchSubmodules = false;
       };