[orca-list] GDM not speaking the "Not listed" option

[Nick Wood <nick microlitesoftware co uk>]

Hi all,

Apologies as I've noticed this bug a while ago and not got around to 
reporting it.

In GDM, the last item in the list of users is always "Not listed".

Orca just says "button" when you land on this item using the arrow keys.

I'm pretty sure this coincided with an Orca update but I have no idea when.

Steps to reproduce:
1. When the GDM login screen appears, use the down arrow to move through 
the list of users until you get to the bottom of the list.
2. The last item should be the "Not listed" option but Orca doesn't 
announce it and just says "button".

I've also noticed that the list of users used to get announced as the 
display name and the username of each user, but now Orca just announces 
the display name.

Can anyone else reproduce?

Thanks,

Nick