BEIJING, Nov. 23 (Xinhua) — China's cyberspace regulator has issued a circular calling for an internet-wide boycott of entertainers who have broken the law or transgressed social morality. There will be no room for such entertainers to seek a comeback by circumventing restrictions, the Office of the Central Cyberspace Affairs Commission said in the circular. Celebrity-related content promoting vulgar information or containing fake online reviews, unproven stories about entertainers or irrational acts of idol-worship, among other content, is prohibited on the internet, the office said. Content involving entertainers endorsing products, services, brands or for-profit events can only appear as advertisements…