[BRLTTY] Yet another way to break brltty

[Amanda Lacy]

Or at least make it unusable.

The Braille presentation menu use to have the options 6-dot computer
Braille, 8-dot computer Braille and contracted. The third option now
shows nothing but full cells (all 8 dots) instead of contracted. I
selected this option to see what would happen. Now my display shows
nothing but all 8 dots, for everything, forever. I can see the
"Preferences menu" message but beyond that everything is dotted out.
What is this feature for?