Fix curses cursor keys

My change to allow fuzzer run in curses caused the cursor keys
to not work (eg. paging through menus with left and right cursor),
so fix that.

win/curses/cursdial.c

@@ -1487,7 +1487,7 @@ menu_get_selections(WINDOW *win, nhmenu *menu, int how)
     menu_display_page(menu, win, curpage, selectors, groupaccels);
 
     while (!dismiss) {
-        curletter = curses_read_char();
+        curletter = curses_getch();
 
         if (curletter == ERR) {
             num_selected = -1;