libgnt/libgnt

Point to the proper url for symbols deprecated in version 3.0. Fixes LIBGNT-9

Testing Done:
Built the docs and verified the link works locally.

Reviewed at https://reviews.imfreedom.org/r/187/
#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;
}