The main suspect in a plot to attack a Taylor Swift concert in Vienna allegedly planned to drive his car into a crowd of fans on either Thursday or Friday, with the goal of killing as many people as possible, the investigation has shown. The man, 19, had planned to use an explosive device and cutting and stabbing weapons in the attack outside the Ernst Happel Stadium, where the US superstar was scheduled to perform, investigators said on Friday. The suspect has fully confessed, according to police. Swift’s three Viennese concerts were cancelled for security reasons, leaving tens of thousands o…