Update session-host-update.md

Added bug on current configuration version to known issues.

Author: cmckitterick

articles/virtual-desktop/session-host-update.md

@@ -93,6 +93,8 @@ With only a reduced number of session hosts available, you should schedule an up
 
 Here are known issues and limitations:
 
+- The current session host configuration version is not displayed in the session host blade in the portal. Until it is fixed, you can access the portal using this URL to view the current configuration version: https://portal.azure.com/?feature.hostpoolVirtualMachinesBladeV3=false#home
+
 - Session host update is only available in the global Azure cloud. It isn't available in other clouds, such as Azure US Government or Azure operated by 21Vianet.
 
 - For session hosts that were created from an Azure Compute Gallery shared image that has a purchase plan, the plan isn't retained when the session hosts are updated. To check whether the image you use for your session hosts has a purchase plan, you can use [Azure PowerShell](/azure/virtual-machines/windows/cli-ps-findimage) or [Azure CLI](/azure/virtual-machines/linux/cli-ps-findimage).