tests/test_replay: Fix error after changes in swh-journal API
See https://jenkins.softwareheritage.org/job/DOBJSRPL/job/tests/218/console
Migrated from D4455 (view on Phabricator)
See https://jenkins.softwareheritage.org/job/DOBJSRPL/job/tests/218/console
Migrated from D4455 (view on Phabricator)