Remove admonition on outdated Azure feature requirement

Author: codyhoag

modules/installation-about-custom-azure-vnet.adoc

@@ -21,11 +21,6 @@ In {product-title} {product-version}, you can deploy a cluster into an existing
 
 By deploying {product-title} into an existing Azure VNet, you might be able to avoid service limit constraints in new accounts or more easily abide by the operational constraints that your company's guidelines set. This is a good option to use if you cannot obtain the infrastructure creation permissions that are required to create the VNet.
 
-[IMPORTANT]
-====
-The use of an existing VNet requires the use of the updated Azure Private DNS (preview) feature. See link:https://azure.microsoft.com/en-us/updates/announcing-preview-refresh-for-azure-dns-private-zones-2/[Announcing Preview Refresh for Azure DNS Private Zones] for more information about the limitations of this feature.
-====
-
 [id="installation-about-custom-azure-vnet-requirements_{context}"]
 == Requirements for using your VNet