deposit: Reuse config.load_from_envvar for configuration loading
This is what the current code inlined is doing already. This code was anterior to the function being born in swh.core.config
Test Plan
tox
Migrated from D4179 (view on Phabricator)
Staging instance, all changes can be removed at any time
This is what the current code inlined is doing already. This code was anterior to the function being born in swh.core.config
tox
Migrated from D4179 (view on Phabricator)