[services] Dev mode - Fix Backup service

Summary: Fix dev mode in backup service. Until now it seems like it was broken.

Test Plan:

docker-compose down
yarn test-blob-service-dev-mode
yarn test-backup-service-dev-mode

Reviewers: jimpo, palys-swm

Reviewed By: jimpo, palys-swm

Subscribers: ashoat, palys-swm, Adrian, atul, benschac, yayabosh

Differential Revision: https://phabricator.ashoat.com/D3695