RHIDP-5456: Updated broken link Authorization Guide (#836)

* updated broken link

* Incorporated Heena's comments

modules/authorization/proc-enabling-the-rbac-plugin.adoc

@@ -7,7 +7,7 @@ Enable the RBAC plugin and declare policy administrators to start using RBAC fea
 The permission policies for users and groups in the {product-short} are managed by permission policy administrators. Only permission policy administrators can access the Role-Based Access Control REST API.
 
 .Prerequisites
-* You have link:{linkadminguide}#assembly-add-custom-app-file-openshift_admin-rhdh[added a custom {product-short} application configuration], and have sufficient permissions to modify it.
+* You have link:{configuring-book-url}[added a custom {product-short} application configuration], and have necessary permissions to modify it.
 * You have link:{authentication-book-title}[enabled an authentication provider].
 
 .Procedure