Broken development environment

Steps to reproduce

1. Follow the instructions described at https://docs.funkwhale.audio/contributing.html#setup-your-development-environment
2. Open http://localhost:8000

What happens?

Funkwhale won't load:

api_1           | 2022-03-02 12:18:28,822 django.request ERROR    Internal Server Error: /
api_1           | Traceback (most recent call last):
api_1           |   File "/venv/lib/python3.9/site-packages/django/core/handlers/exception.py", line 47, in inner
api_1           |     response = get_response(request)
api_1           |   File "/app/./funkwhale_api/common/middleware.py", line 241, in __call__
api_1           |     return serve_spa(request)
api_1           |   File "/app/./funkwhale_api/common/middleware.py", line 38, in serve_spa
api_1           |     html = get_spa_html(settings.FUNKWHALE_SPA_HTML_ROOT)
api_1           |   File "/app/./funkwhale_api/common/middleware.py", line 112, in get_spa_html
api_1           |     return get_spa_file(spa_url, "index.html")
api_1           |   File "/app/./funkwhale_api/common/middleware.py", line 132, in get_spa_file
api_1           |     response.raise_for_status()
api_1           |   File "/venv/lib/python3.9/site-packages/requests/models.py", line 960, in raise_for_status
api_1           |     raise HTTPError(http_error_msg, response=self)
api_1           | requests.exceptions.HTTPError: 502 Server Error: Bad Gateway for url: http://nginx/front/index.html
api_1           | INFO:     172.28.0.7:33818 - "GET / HTTP/1.1" 500 Internal Server Error

What is expected?

Funkwhale front page loads.

Context

Funkwhale version(s) affected: develop