Version 0.3.0 does not work on python:3.9 docker image

[frepond]

Previous version v0.2.0 used to work without problem on official python docker image python:3.9. After upgrading to v0.3.0, it doesn't work anymore, it fails to connect.

pymongo.errors.ServerSelectionTimeoutError: localhost:57005: [Errno 111] Connection refused, Timeout: 3.0s, Topology Description: <TopologyDescription id: 6139179143478f2bdc7aad06, topology_type: Single, servers: [<ServerDescription ('localhost', 57005) server_type: Unknown, rtt: None, error=AutoReconnect('localhost:57005: [Errno 111] Connection refused')>]>
.venv/lib/python3.9/site-packages/pymongo/topology.py:218: ServerSelectionTimeoutError