ANPEE: Auto rotation doc update

Only Standard Microsoft SKU supports certificate auto rotation. Updated the doc with the same. Pls refer to WI https://msazure.visualstudio.com/One/_workitems/edit/15128275 for more details.

Author: gitanjali1993

articles/cdn/cdn-custom-ssl.md

@@ -198,7 +198,7 @@ Grant Azure CDN permission to access the certificates (secrets) in your Azure Ke
 
     > [!NOTE]
     > * Azure CDN only supports PFX certificates.
-    > * In order for the certificate to be automatically rotated to the latest version when a newer version of the certificate is available in your Key Vault, please set the certificate/secret version to 'Latest'. If a specific version is selected, you have to re-select the new version manually for certificate rotation. It takes up to 72 hours for the new version of the certificate/secret to be deployed.
+    > * In order for the certificate to be automatically rotated to the latest version when a newer version of the certificate is available in your Key Vault, please set the certificate/secret version to 'Latest'. If a specific version is selected, you have to re-select the new version manually for certificate rotation. It takes up to 72 hours for the new version of the certificate/secret to be deployed. Only Standard Microsoft SKU supports certificate auto rotation.
 
 5. Select **On** to enable HTTPS.