accessibility: use real TTY cursor in room list

[humenda]

The :rooms list uses a visual cursor instead of the "real" TTY cursor. This
one stays either at the end or the beginning of the list. This is problematic
for blind users using a screen reader. The cursor is used to determine which
item is selected.
You can compare this on GNU/Linux when using dialog, once without
--visit-items and once with --visit-items. Without this change, a blind user
can just learn the room list and their indices by heart, navigate to the
memorised index and hope they'll end up in the right room.