A 19-year-old man who had pledged allegiance to the Islamic State militant group has confessed to plotting an attack on the Vienna leg of Taylor Swift’s Eras tour, Austrian security authorities said on Thursday. He had wanted to use home-made bombs and knives to kill people during one of Swift’s performance, said Omar Haijawi-Pirchner, director of state security and intelligence in the Austrian Interior Ministry. The 19-year-old did not have a concert ticket but intended to strike near the Ernst Happel Stadium. He was part of an Islamist network and already on the police’s radar, the official …