Describe the bug

The request for static files for the django admin interface returns a 404.
At a guess, the locations for /media/admin and /static/admin in the nginx configuration (in /conf/nginx.conf) expect a python 3.7 virtualenv but the set_up_virtualenv function (in scripts/_common.sh) use the generic python3 executable.
This can end up with a missmatch between expected and actual path (in my case venv/lib/python3.7/ instead of venv/lib/python3.9/).

I tried changing both locations in /conf/nginx.conf before installing the app, and the django admin interface worked as expected.

Context

• Hardware: Other ARM board, A20-OLinuXino-Lime2
• YunoHost version: 11.0.11
• I have access to my server: everything
• Are you in a special context or did you perform some particular tweaking on your YunoHost instance?: Yunohost installed over a fresh armbian
• Using, or trying to install package version/branch: 2.11.20220622~ynh2

Steps to reproduce

1. Install app
2. Go to the django admin interface of the app (https://APP_URL/admin/
3. All static files return a 404 error, the admin interface is an almost unusable mess

Expected behavior

The static files are requested from the correct url and the admin interface is rendered correctly