Handle creation of CampaignSpecs without ChangesetSpecs correctly
Created by: mrnugget
I ran into this while testing the reconciler: when you create a CampaignSpec with 0 ChangesetSpecs and apply it, you should end up with a Campaign that has 0 Changesets.
What you instead get is a Campaign with all the ChangesetSpecs that were
lying around in your database, because the ListChangesetSpecs
call returns
all ChangesetSpecs if RandIDs
is empty.
This fixes that.