Follow-up of: https://jira.ez.no/browse/EZP-20638

After synchronizing an object with related objects, its related objects do not maintain their original order.

Steps to reproduce:

1. Create an object (i.e, an Article), publish it
2. Sync. changes to the target server
3. Edit the object once more, add multiple object relations
4. Sync. changes, and verify that, on the target, the related objects for the object we've created do not maintain their order)