for jepsen: extra online spare

[jerrytesting]

While running raft-v0.17.1, Jepsen harness reports the for Jepsen: extra online spare error. Your Jepsen harness configures the keyword for jepsen as assertion-pattern, so I think this is the abnormal behaviour that your want to avoid.

Here is the whole logs: https://github.com/jerrytesting/craft_extra_online_spare

[cole-miller]

Yep, we've seen this in our jepsen.dqlite CI periodically as well. It's less serious than a crash or a segfault, but definitely wants looking into.