Steps to reproduce

Use mediawiki 1.28 wmf 1 which you can find here

• https://github.com/wikimedia/mediawiki/tree/wmf/1.28.0-wmf.1

• https://github.com/wikimedia/mediawiki-vendor/tree/wmf/1.28.0-wmf.1

Actual results

• Visting mw-config is showing the text like <config-title> and so on.

Expected results

• It should show text instead of things like <config-title>

In mediawiki 1.27 wmf 23 mw-config worked. Upgrading to 1.28 wmf1 broke i18n for mw-config