Update nginx configuration and switch to runserver_plus in devcontainer setup

[lucasmarchd01]

This change disables nginx's error page interception for the development environment configuration file to ensure that Django's debug pages are displayed correctly when DEBUG is set to True. I think that this change was introduced as part of #1530 which should be done instead on the cantusdb.conf file on the production server. (Related: #1598)

Replaced runserver with runserver_plus in the Docker Compose configuration for the development container.

[dchiller]

Good catch on the proxy_intercept_errors. I made the change in development (where you're right, it shouldn't be) but never actually did it in the playbooks :(

Made a PR for that here: https://github.com/dact-chant/ansible.cantus-db/pull/48