Matt Lauer showed his groupie side the other night at Radio City at a performance by Irish rockers The Script. “Matt was backstage, wishing them good luck, before the show,” says a spy. “He watched from the back with Epic Records’ LA Reid. He was bobbing his head and singing to their song ‘Hall of Fame.’ ” The band has been on the “Today” show 10 times in three years, including an appearance Tuesday morning during which Lauer joked about how they invited him to a pub during the London Olympics but then never called to follow up. After their performance on the TV program, a witness says Lauer asked them for a ticket to the evening concert, which they happily provided.