painting: evade an ncurses bug by adding the A_PROTECT attribute

Adding the obscure A_PROTECT attribute to every color prevents an
occasional miscoloring of the first few rows on the screen -- when
ncurses is version 6.0 and dates from before October 17, 2015.

Original-idea-by: Brand Huntsman <alpha@qzx.com>
Tested-by: Brand Huntsman <alpha@qzx.com>

This fixes https://savannah.gnu.org/bugs/?52182.
1 file changed