Revive CollagenIn case you were wondering: yes, the Spice Girls do have a group chat. Except these days, it’s less about world tours and more about a very different stage of life.“We have lots of group chats about menopause,” Mel B tells me, sitting in a TriBeCa hotel suite in a bright purple skirt suit and towering heels (a subtle nod to her Scary Spice era). For the 50-year-old pop icon, those conversations reflect a bigger shift in how she th…