Further fix to configuration classes using ISet, resolving regression with custom 404 pages#19573

kjac merged 1 commit intomainumbraco/Umbraco-CMS:mainfrom

v16/bugfix/fix-config-for-error-404-collectionumbraco/Umbraco-CMS:v16/bugfix/fix-config-for-error-404-collectionCopy head branch name to clipboard