PROVIDENCE — The city’s Board of Licenses ordered the immediate closure of Club Ultra after two men were stabbed in the nightclub early Saturday morning, authorities said.The action was taken, pending a full hearing by the board on Monday, according to Providence police Lt. David Allen.The closure of the club at 172 Pine St was in response to the stabbings of a 36-year-old man and a 38-year-old man at about 1:30 a.m.