franz: use wrapGAppsHook

I encountered crashes while opening the file selection dialog.

```
(franz:11597): GLib-GIO-ERROR **: 14:08:20.102: No GSettings schemas are installed on the system
[1]    11597 trace trap  franz
```

This error is also presented in various other gtk applications (e.g. https://github.com/NixOS/nixpkgs/issues/45286). I used the same trick to fix this error.