Update index.md (#20166)

Author: Rick-Anderson

aspnetcore/security/authentication/azure-active-directory/index.md

@@ -25,8 +25,6 @@ These tutorials and samples demonstrate authentication in ASP.NET Core using Mic
 
 * [Enable your ASP.NET Core app to sign-in users and call web APIs using Azure AD V2](/samples/azure-samples/active-directory-aspnetcore-webapp-openidconnect-v2/enable-webapp-signin/): 
   * See [this associated video](https://channel9.msdn.com/Events/Build/2018/THR5001)
-
 * [Calling an ASP.NET Core 2.0 Web API from a WPF application using Azure AD V2](/samples/azure-samples/active-directory-dotnet-native-aspnetcore-v2/calling-an-aspnet-core-web-api-from-a-wpf-application-using-azure-ad-v2/): 
   * See [this associated video](https://channel9.msdn.com/Events/Build/2018/THR5000)
-
-* [An ASP.NET Core web API with Azure AD B2C](https://azure.microsoft.com/resources/samples/active-directory-b2c-dotnetcore-webapi/)
+* [An ASP.NET Core web app with Azure AD B2C](/samples/azure-samples/active-directory-b2c-dotnetcore-webapp/an-aspnet-core-web-app-with-azure-ad-b2c/)