Pope Leo took a huge “risk” when he travelled in the popemobile for the first time during his inauguration today, according to a security expert. As he made his way across St. Peter’s Square in the Vatican before being sworn in, the first-ever American pope greeted the throngs of supporters who had gathered to catch a glimpse of him. The historic ceremony was also drawing in world leaders and royals from all around the world, with US vice president JD…