BZ#2014982: adding missing link to how cluster is configured to trust the update server hosted by osus

Author: skrthomas

updating/installing-update-service.adoc

@@ -83,6 +83,11 @@ and must be no more than 63 characters`, try creating the Update Service with a
 
 include::modules/update-service-configure-cvo.adoc[leveloffset=+2]
 
+[NOTE]
+====
+See xref:../networking/enable-cluster-wide-proxy.adoc#nw-proxy-configure-object[Enabling the cluster-wide proxy] to configure the CA to trust the update server. 
+====
+
 [id="update-service-delete-service"]
 == Deleting an OpenShift Update Service application