Justin Timberlake performed a surprise concert in Las Vegas this week at the opening of the Fontainebleau Hotel. The black-tie crowd included celebrities like Kim Kardashian, Kendall Jenner, Tom Brady, Keith Urban, and Sylvester Stallone. Timberlake didn’t mention the highly-publicized accusations Britney Spears made about him in her recent memoir, but he did say “no…