Kate Middleton’s uncle Gary Goldsmith is using his Celebrity Big Brotherdebut to slam Meghan Markle after the Duchess of Sussex branded his niece as “formal.” “I have the opinion that Harry was, really loved, massively loved, and when they were a threesome — Kate, William and Harry — were really comfortable together, loved,” Goldsmith said on the reality show. “And then suddenly there’s an extra dynamic that comes in, puts a stick in the spokes and creates so much drama that I don’t generally think is there, and rewrote the history and said how unhappy he was, and I just don’t think that’s fai…