(AzureCXP) updating link

Updated link for "MySQL in-app" under "What gets backed up" section.
https://github.com/MicrosoftDocs/azure-docs/issues/38791

Author: Grace-MacJones-MSFT

articles/app-service/manage-backup.md

@@ -36,7 +36,7 @@ The following database solutions are supported with backup feature:
    - [SQL Database](https://azure.microsoft.com/services/sql-database/)
    - [Azure Database for MySQL](https://azure.microsoft.com/services/mysql)
    - [Azure Database for PostgreSQL](https://azure.microsoft.com/services/postgresql)
-   - [MySQL in-app](https://blogs.msdn.microsoft.com/appserviceteam/2017/03/06/announcing-general-availability-for-mysql-in-app)
+   - [MySQL in-app](https://azure.microsoft.com/en-us/blog/mysql-in-app-preview-app-service/)
 
 
 > [!NOTE]