A Phase 2b Randomized, Double-Blind, Placebo-Controlled, Multicenter, Dose-Ranging Study to Evaluate the Efficacy and Safety Profile of PF-06651600 With a Partially Blinded Extension Period to Evaluate the Efficacy and Safety of PF-06651600 and PF-06700841 in Subjects With Active Non-Segmental Vitiligo. A Phase 2b Randomized, Double-Blind, Placebo-Controlled, Multicenter, Dose-Ranging Study to Evaluate the Efficacy and Safety Profile of PF-06651600 With a Partially Blinded Extension Period to Evaluate the Efficacy and Safety of PF-06651600 and PF-06700841 in Subjects With Active Non-Segmental Vitiligo.