The owner of a Westboro self-storage company accused of locking a Verizon worker in an airtight underground vault told cops “that’s not my problem” when they tried to explain the dangerousness of what he’d done, police said.Cops say Howard W. Cook, the owner of Westboro Self Storage, yelled down at a Verizon technician who was working in an underground vault to move his van, which was parked in a grassy area near his business about 3:30 p.m.