libgnt/libgnt

Remove volatile from GntBindable registration.

2021-05-26, Elliott Sales de Andrade
81827d41b859
Remove volatile from GntBindable registration.

This causes a warning with GLib 2.67 and GCC 11.

Testing Done:
Compiled and saw no warnings.

Reviewed at https://reviews.imfreedom.org/r/674/
#include <ncurses.h>
int main()
{
int ch;
initscr();
noecho();
cbreak();
refresh();
WINDOW *win = newpad(20, 30);
box(win, 0, 0);
prefresh(win, 0, 0, 0, 0, 19, 29);
doupdate();
while ((ch = getch())) {
printw("%d ", ch);
refresh();
}
endwin();
return 0;
}