Britney Spears has paid tribute to the late Princess Diana with a sweet admiration post on Instagram.The pop singer, who enjoyed a rare outing with boyfriend Sam Asghari recently, took to the social media platform to praise the Princess of Wales.The 39 year old shared one image of Diana, and another of an army of loyal fans waiting to get a glimpse of the mother-of-two when she was still alive. She captioned it: "She never wanted to be the queen...