Wire autorun at start

When I enable the option to autostart, it doesn't work.

Checking the file on ~/.config/autostart/wire-desktop.desktop, it seems to point to exec:
```
Exec=/app/Wire/wire-desktop --hidden
```

which doesn't exist. Should the desktop file be patched to full flatpak exec command line ? Like example:

```
Exec=flatpak run com.wire.WireDesktop/x86_64/stable --hidden
```