Comment 3 for bug 1874400

To process the first payload without revision_number we could potentially make the comparison

if orig and orig.get('revision_number', -1) >= payload.get('revision_number', 0):
    return True

So if the orig is empty or revision_number is zero (First time) We still process the first message and not discard it. I tested this

 + if orig.get('revision_number', 0) > payload.get('revision_number', 0):

in production this didn't cause any issues.