darktable: lua support requires lua 5.3

https://github.com/NixOS/nixpkgs/issues/33710#issuecomment-356680711

Fixes #33710.

pkgs/top-level/all-packages.nix

@@ -14453,6 +14453,7 @@ with pkgs;
 
   darktable = callPackage ../applications/graphics/darktable {
     inherit (gnome2) GConf libglade;
+    lua = lua5_3;
     pugixml = pugixml.override { shared = true; };
   };