Orca doesn't read LXQt notifications

Orca doesn't read anything when I make a notification with
```
notify-send -a 'Test' -t 3000 -i emblem-downloads 'Download' 'This is a test'
```
But the right click menu of lxqt-notificationd's tray icon is read by Orca correctly. I tested under Wayland.

I don't see a reason that this could have been caused by our code, but it would be nice if a dev could investigate it.
