language lost in admin page when adding a plugin

[sampaccoud]

Bug Report

Problematic behavior/code The side toolbar is shown in the preferred language of the browser, not in the language of the current page.

Expected Behavior The language in which the admin is navigating should be respected in the side toolbar.

Steps to Reproduce

1. Go to a page in a language different from your browser's preferred language (e.g. on https://www.fun-mooc.fr/en/)
2. Open the side toolbar
3. Notice that it is shown in your browser's preferred language

https://user-images.githubusercontent.com/1427165/153637955-0ec1b90d-5924-4169-8b5a-b26d336d5687.mp4

Environment

• Richie version: 2.12.0
• Platform: Docker

Possible Solution This may be a DjangoCMS bug