Change password login page 'Username or Email' field to just 'Email' (#9877)

Author: advay26

src/NuGetGallery/ViewModels/LogOnViewModel.cs

@@ -49,8 +49,8 @@ public enum ExistingUserLinkingErrorType
     public class SignInViewModel
     {
         [Required]
-        [Display(Name = "Username or Email")]
-        [Hint("Enter your username or email address.")]
+        [Display(Name = "Email Address")]
+        [Hint("Enter your email address.")]
         public string UserNameOrEmail { get; set; }
 
         [Required]