adslib: add updateScript

pkgs/by-name/ad/adslib/package.nix

@@ -2,6 +2,7 @@
   lib,
   stdenv,
   fetchFromGitHub,
+  unstableGitUpdater,
 }:
 
 stdenv.mkDerivation {
@@ -20,6 +21,8 @@ stdenv.mkDerivation {
     cp adslib.so $out/lib/adslib.so
   '';
 
+  passthru.updateScript = unstableGitUpdater { };
+
   meta = {
     description = "Beckhoff protocol to communicate with TwinCAT devices";
     homepage = "https://github.com/stlehmann/ADS";