Taylor Swift’s security presence has reportedly been stepped up to “presidential levels” ahead of her London shows. The singer is due to perform five nights at Wembley Stadium in the UK capital between 15 and 20 August marking her return to the stage for the first time since police in Austria foiled a plan to attack her concerts at the Ernst Happel Stadium in Vienna – and a new report suggests her security has been stepped up to levels usually reserved for U.S presidents. A source told The Sun newspaper the singer now has “presidential level” security around her. An insider added: “Taylor’s se…