Help-all flag is not removed from required options error message

[jakoblover]

If x amount of options from a group is required, the help-all flag will be displayed in addition to the other options, while the normal help flag has been removed from the list. Help-all should also be removed from this list if set_help_all_flag() has been set

Output:

At least 1 option from [--help-all,.....]  is required
Run with --help or --help-all for more information.

Code that should be fixed resides in App.hpp

if(require_option_min_ > used_options || (require_option_max_ > 0 && require_option_max_ < used_options)) {
            auto option_list = detail::join(options_, [](const Option_p &ptr) { return ptr->get_name(false, true); });
            if(option_list.compare(0, 10, "-h,--help,") == 0) {
                option_list.erase(0, 10);
            }
            auto subc_list = get_subcommands([](App *app) { return ((app->get_name().empty()) && (!app->disabled_)); });
            if(!subc_list.empty()) {
                option_list += "," + detail::join(subc_list, [](const App *app) { return app->get_display_name(); });
            }
            throw RequiredError::Option(require_option_min_, require_option_max_, used_options, option_list);
        }