Currently, it is possible for a node to erroneously update its own lastAppliedOptime when all of these conditions are true:

• the node is PRIMARY
• the node was SECONDARY in the past and has chained through another secondary
• the node does further writes before receiving a handshake from the chaining secondary

In such a situation, we rewind our own optime in the slavemap, but do not update the legacy replset's lastappliedoptime, which causes an fassert failure.