Claudia Schiffer proved once again age is but a number by celebrating her 54th birthday in a bikini. The supermodel flaunted her trim figure in a sizzling video after saying aging should be “celebrated and revered”, RadarOnline.com can reveal. Schiffer posted the video from her birthday trip to Greece on her Instagram page. The 54-year-old looked fit as ever in a tiny white bikini that showed off her toned abs. In the footage she marvels at a butterfly fluttering around her before it landed on her hand. She captioned the post: “The Greek butterfly came back this year for my birthday 🦋 Thank yo…