Hi, I've been using Whatsapp in US for the past few years. And am planning to return to india. I will be getting a new SIM in india, and will be abandoning my old US number. I have a question about Whatsapp's "Phone Number Change" .. Do I need both teh old and new numbers active? Or, Is it OK if my old number is deactivated (Or At least, now working after I move countries)