duti: update homepage

pkgs/os-specific/darwin/duti/default.nix

···
     maintainers = with maintainers; [matthewbauer];
     platforms = platforms.darwin;
     license = licenses.publicDomain;
-    homepage = "http://duti.org/";
+    homepage = "https://github.com/moretension/duti/";
   };
 }