Steps to reproduce:
- Set in [[Special:Preferences]]
- Skin "Vector".
- Enable "Use live preview".
- Open https://en.wikipedia.org/w/index.php?title=MediaWiki&action=edit&useskin=monobook
- Click on "Show preview".
The languages on the left side has the design from skin Vector.
Expected result: Show the languages in the design of the current skin instead of the design of the skin of the user settings.
Solution: Use current skin for preview loading.