A United Airlines flight from Barcelona to Newark was diverted to Logan International Airport this afternoon after a “pressurization issue in the cabin,” the airline said. The Boeing 757 was carrying 113 passengers and 7 crew, the airline said in a statement. It landed safely and with no problems at 3:03 p.m. The airline said it was arranging for an alternate aircraft to carry the passengers to Newark and would “accommodate them to their final destinations.”