Docs: Extending - upgrade external db docs - with respect of postgresql v12
Omnibus works with PostgreSQL 12, but pg_dump
+ pg_restore
need to be of version 12 as well.
Otherwise gitlab-backup create
will fail while receiving a version mismatch error.
Additional explanation can be seen under https://gitlab.zendesk.com/agent/tickets/160121 (internal ZD ticket)
Edited by GitLab Release Tools Bot