The automember-rebuild task may require high CPU usage if many users/hosts/groups are processed. Add a note in the ipa automember-rebuild CLI output and in the WebUI confirmation message. Fixes: https://pagure.io/freeipa/issue/9320 Signed-off-by: Florence Blanc-Renaud <flo@redhat.com> Reviewed-By: Francisco Trivino <ftrivino@redhat.com>