Fix Weibo email scope detection

Author: kinosang

src/AspNet.Security.OAuth.Weibo/WeiboAuthenticationHandler.cs

@@ -68,7 +68,7 @@ protected override async Task<AuthenticationTicket> CreateTicketAsync([NotNull]
             // When the email address is not public, retrieve it from
             // the emails endpoint if the user:email scope is specified.
             if (!string.IsNullOrEmpty(Options.UserEmailsEndpoint) &&
-                !identity.HasClaim(claim => claim.Type == ClaimTypes.Email) && Options.Scope.Contains("user:email"))
+                !identity.HasClaim(claim => claim.Type == ClaimTypes.Email) && Options.Scope.Contains("email"))
             {
                 identity.AddOptionalClaim(ClaimTypes.Email, await GetEmailAsync(tokens), Options.ClaimsIssuer);
             }