Superhero film “The Old Guard” is renewing attention in Morocco’s imperial city of Marrakech, the setting of a magical centuries-long battle between its star-studded protagonists. Released on streaming service Netflix July 10, the action flick has received solid reviews for its dramatic sequences and star performance by Charlize Theron. It has also opened viewers’ eyes to the ancient beauty and charm of Marrakech, a popular tourist spot whose old medina ...