When the master's log has all entries from version 1 to now, and no
uber entry (legacy master), then new slaves will not pull version 1,
because their uber record has version 1.
The fix is to force the uber version to 0 always, and avoid adding a
truncate nop when doing a full prop. The uber record now records the
database version even in the absence of any other log entries so that
we know what to pull going forward.
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