Update support policies for nsgs

Author: Karan Magdani

articles/openshift/support-policies-v4.md

@@ -25,7 +25,7 @@ Certain configurations for Azure Red Hat OpenShift 4 clusters can affect your cl
 * Don't remove or modify the cluster Prometheus service.
 * Don't remove or modify the cluster Alertmanager service or Default receiver. It *is* supported to create additional receivers to notify external systems.
 * Don't remove Service Alertmanager rules.
-* Security groups can't be modified. Any attempt to modify security groups will be reverted.
+* The ARO provided Network Security Group can't be modified nor replaced. Any attempt to modify or replace it will be reverted
 * Don't remove or modify Azure Red Hat OpenShift service logging (mdsd pods).
 * Don't remove or modify the 'arosvc.azurecr.io' cluster pull secret.
 * All cluster virtual machines must have direct outbound internet access, at least to the Azure Resource Manager (ARM) and service logging (Geneva) endpoints.  No form of HTTPS proxying is supported.