fix error page code 404 can not preview on CMS

[pack254]

Description

this PR is fixed the issue #904

Issues

• Error page type with 404 code can’t preview in CMS #904

Pull request checklist

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• [ ] This change is covered with tests (or tests aren't necessary for this change)
• [ ] Any relevant User Help/Developer documentation is updated; for impactful changes, information is added to the changelog for the intended release
• CI is green

[tractorcow]

Thank you @pack254 appreciate your contribution. Can anyone merge this once the build passes?