fix namespaces in LoginPartial

src/Services/Identity/Identity.API/Views/Shared/_LoginPartial.cshtml

@@ -1,5 +1,5 @@
 @using Microsoft.AspNetCore.Identity
-@using Identity.API.Models
+@using Microsoft.eShopOnContainers.Services.Identity.API.Models
 
 @inject SignInManager<ApplicationUser> SignInManager
 @inject UserManager<ApplicationUser> UserManager