Fix current_credits_list_index not always being reset

If you go into the middle of the list of translators in the main menu
credits, then press Escape, and then go into the credits again, the
first page of the list may start at the wrong place, because while
game.translator_credits_pagenum was reset to 0,
game.current_credits_list_index wasn't. This is fixed now.

desktop_version/src/Input.cpp

@@ -1591,6 +1591,7 @@ static void menuactionpress(void)
             //next page
             music.playef(Sound_VIRIDIAN);
             game.translator_credits_pagenum = 0;
+            game.current_credits_list_index = 0;
             game.createmenu(Menu::credits_localisations_translations, true);
             map.nexttowercolour();
             break;