This fix is analogous to d5a3ae6008e4399b336f3a72d8dee328f97a0002. As of 84a1984b7cb70c74eaf517ffc424228fa954ed37 we set query_epoch to a lower
value reliably, but we need to encode the latest epoch for pre-nautilus
OSDs because they do not set last_peering_epoch reliably and havin a lower
query_epoch will cause them to discard this message.