Clarify sidekiq negate setting

doc/administration/operations/extra_sidekiq_processes.md

@@ -95,14 +95,14 @@ To view the Sidekiq processes in GitLab:
 
 ## Negate settings
 
-To have the additional Sidekiq processes work on every queue **except** the ones
+To have the Sidekiq process work on every queue **except** the ones
 you list. In this example, we exclude all import-related jobs from a Sidekiq node:
 
-1. After you follow the steps for [starting extra processes](#start-multiple-processes),
-   edit `/etc/gitlab/gitlab.rb` and add:
+1. Edit `/etc/gitlab/gitlab.rb` and add:
 
    ```ruby
    sidekiq['negate'] = true
+   sidekiq['queue_selector'] = true
    sidekiq['queue_groups'] = [
       "feature_category=importers"
    ]