Dict's get method does not take keyword argument

Prior to this, i was unable to start the swh-lister within the docker-dev (with fresh update on the container)

The failure is detailed below [1]

Note: and mypy does not complain ;)

• [1] Related !109 (closed)

Test Plan

• tox
• doco up -d swh-lister (with local override) -> it starts now

---

Migrated from D2059 (view on Phabricator)