Stop modify price html for guest role

Prevent modification of price HTML for guest roles.

// Stop modify price html for guest role
add_filter('advanced_woo_discount_rules_modify_price_html', function($modify, $price_html, $product, $quantity) {
    if (!is_user_logged_in()) {
        $modify = false;
    }
    return $modify;
}, 100, 4);