FEATURE: Add site setting to disable staged user cleanup

... and disabled the cleanup during imports, otherwise a running Sidekiq might delete users before posts are created

script/import_scripts/base.rb

@@ -81,7 +81,9 @@ class ImportScripts::Base
       disable_emails: 'yes',
       max_attachment_size_kb: 102400,
       max_image_size_kb: 102400,
-      authorized_extensions: '*'
+      authorized_extensions: '*',
+      clean_up_inactive_users_after_days: 0,
+      clean_up_unused_staged_users_after_days: 0
     }
   end