Rod Stewart is not mincing words about the president, especially in the company of British royalty. The rocker appeared to refer to Donald J. Trump as “that little ratbag” when he greeted King Charles in a receiving line at an event Monday night in London. “May I say, well done in the Americas,” Stewart can be heard saying in video captured of their meeting, with Ronnie Wood standing alongside him. “You were superb, absolutely superb… put that little ratbag in his place.” Charles’ back is to the camera in the video, so it’s unclear exactly how the monarch responded.…