By Chiara Fiorillo & Laura Elston Prince Harry has made a surprise appearance on screen at the Sport Gives Back Awards in honour of a triple amputee Afghanistan veteran. In a video message paid at the event in London, the Duke of Sussex paid tribute to Invictus medal-winning cyclist and fellow former soldier Josh Boggi, who won the Unconquered category. It was Harry’s second video appearance on Wednesday, coming on the same day he lost a High Court challenge against the Home Office over a decision to change the level of his personal security when he visits the UK. The duke, whoalso recorded an…