Taylor Swift’s absences from boyfriend Travis Kelce’s last two NFL games are feared to have been linked to “security concerns”. The ‘Shake it Off’ singer, 34, was at the centre of a major terror scare in August when a thwarted Islamic State-inspired attack on one of her shows forced the cancellation of her Vienna dates. It’s now been highlighted she was a no-show at her 34-year-old NFL star boyfriend’s past two games after spending the last year supporting him at matches. But a source said it had nothing to do with signs she and Travis may be experiencing relationship difficulties – and was mo…