vt: break a couple of obsolete SCOish codes.

No modern terminal supports them, and SGR 38 conflicts with detecting
xterm-256 colours.  This also makes SGR 39 consistent with other popular
terminals.  Neither are used by ncurses' terminfo.

Signed-off-by: Adam Borowski <kilobyte@angband.pl>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>