Remove 'Optional:' from heading (#4320)

Author: aneta-petrova

guides/common/modules/proc_configuring-group-mapping-for-keycloak-authentication.adoc

@@ -1,10 +1,10 @@
 :_mod-docs-content-type: PROCEDURE
 
 [id="configuring-group-mapping-for-keycloak-authentication_{context}"]
-= Optional: Configuring external group mapping for {keycloak} authentication
+= Configuring external group mapping for {keycloak} authentication
 
 [role="_abstract"]
-To implement the role-based access control (RBAC), create a group in {Project}, assign a role to this group, and then map an {keycloak} group to the {Project} group.
+Optionally, to implement the role-based access control (RBAC), create a group in {Project}, assign a role to this group, and then map an {keycloak} group to the {Project} group.
 As a result, anyone in the given group in {keycloak} will log in under the corresponding {Project} group.
 
 For example, you can configure users of the {Project}-admin user group defined in Active Directory to authenticate as users with administrator privileges on {Project}.