Correct rbac section

Signed-off-by: nshankar <[email protected]>

Author: nshankar

articles/aks/istio-plugin-ca.md

@@ -56,7 +56,7 @@ The add-on requires Azure CLI version 2.57.0 or later installed. You can run `az
     ```
 
     > [!NOTE]
-    > If you created your Key Vault with Azure RBAC Authorization, follow the instructions [here][akv-rbac-guide] to create permissions for the managed identity. Add a role assignment for `Key Vault Reader` for the cluster's system-assigned managed identity. 
+    > If you created your Key Vault with Azure RBAC Authorization for your permission model instead of Vault Access Policy, follow the instructions [here][akv-rbac-guide] to create permissions for the managed identity. Add an Azure role assignment for `Key Vault Reader` for the add-on's user-assigned managed identity. 
 
 ## Set up Istio-based service mesh addon with plug-in CA certificates