[BRLTTY] Modify braille representation for the tabulation character

[Kristof Nijs]

Hi all,

Since I did a upgrade from Ubuntu to 16.04, the tabulation character
is represented in braille by the dots 2, 4, 7 and 8. I whould rather
change it to no dots because this makes indentation more clear.

I tought I could do that in /etc/brltty/control-latin.tti but there
are already no dots specified for the tabulation character.

How can I make these changes take effect or is there another way to do this?

Thanx and greetings,
Kristof