By Antony Clements-Thrower The Princess of Wales ’ family are said to be fuming her uncle Gary Goldsmith is preparing to enter the Celebrity Big Brother house this week. Gary, Kate’s mum Carole Middleton’s brother, was spotted doing some last-minute shopping ahead of his arrival on the show on Monday night. Known for his hard partying, his arrival is sure to add to the Princess’ woes as she continues to recuperate at home after abdominal surgery. Her family are said to be furious at his agreeing to take part and fear he could blab family secrets to his housemates. A source told the Sun: “Gary …