A man uses his smartphone to play online casino. (Source: Getty Images) By Andreo Calonzo Philippine President Rodrigo Duterte has signed a law taxing online casinos which cater mostly to Chinese clients, spokesman Harry Roque said at a televised briefing Thursday. Tax collections will be used for universal healthcare and to develop medical facilities, Roque said, adding that law is part of the government’s efforts to regulate all forms of gambling. Under the Senate version of the bill, which Duterte designated as “urgent,” offshore gaming operators must pay 5% tax on their gross gaming revenue, while foreigners employed in online…