Currently if a node that is outside of the config tries to add an entry
or modify config transient error is returned and this causes the node
to retry. But the error is not transient. If a node tries to do one of
the operations above it means it was part of the cluster at some point,
but since a node with the same id should not be added back to a cluster
if it is not in the cluster now it will never be.
Return a new error not_a_member to a caller instead.
Message-Id: <Y42mTOx8bNNrHqpd@scylladb.com>
022a825b33