Panels aren't properly displayed in Edit mode when setting Multilingual to Yes on Colibri

Steps to reproduce:

1. Go to Administration: Localization and set Multilingual to Yes
2. Go to any page and edit it in either the Wiki or WYSIWYG editor; for ex. use http://localhost:8080/xwiki/bin/edit/Sandbox/WebHome

Notice how the panels aren't displayed on the right side of the page. Instead you can see them partially below the page content.

Doesn't reproduce on Flamingo and might be related to the fix for XWIKI-10412.