### Integrated Storage panic related to old TLS key

Raft in Vault uses its own set of TLS certificates, independent of those that the user
controls to protect the API port and those used for replication and clustering. These
certs get rotated daily, but to ensure that nodes which were down or behind on Raft log
replication don't lose the ability to speak with other nodes, the newly generated daily
TLS cert only starts being used once we see that all nodes have received it.

A recent security audit related change results in this rotation code [getting a
panic](https://github.com/hashicorp/vault/issues/15147) when the current cert is
more than 24h old.  This can happen if the cluster as a whole is down for a day
or more. It can also happen if a single node is unreachable 24h, or sufficiently
backlogged in applying raft logs that it's more than a day behind.

Impacted versions: 1.10.1, 1.9.5, 1.8.10.  Versions prior to these are unaffected.

New releases addressing this panic are coming soon.
