Rose Hanbury’s lawyers sent a legal notice to late night host Stephen Colbert after he quipped about gossip of an alleged affair with Prince William, RadarOnline.com has learned. “The rumor appears to have entered into the mainstream media recently as a result of another joke made about it on The Late Show with Stephen Colbert,” lawyers for the British peeress said, revealing they have taken action to squash the speculation once and for all. “We have written on our client’s behalf to CBS and various other reputable media organizations to confirm that the allegation is false,” the lawyers told …