fixed upgrade script update_bucket_owner_account.js

[dannyzaken]

Explain the changes

1. the upgrade script used $find $set in make_changes which only updates a single document.
2. changed to update all necessary buckets

Issues: Fixed #xxx / Gap #xxx

1. BZ 1818147

Testing Instructions:

1. create multiple buckets in a system with version 5.2
2. upgrade to 5.3
3. make sure that read_system works, and in the DB all buckets have owner_account property