raft: don't update gossiper state if raft is enabled early or not enabled at all
raft: don't update gossiper state if raft is enabled early or not enabled at all

There is a listener in the `raft_group_registry`,
which makes the gossiper to re-publish supported
features app state to the cluster.

We don't need to do this in case `USES_RAFT_CLUSTER_MANAGEMENT`
feature is enabled before the usual time, i.e. before the
gossiper settles. So, short-circuit the listener logic in
that case and do nothing.

Also, don't do anything if raft group registry is not enabled
at all, this is just a generic safeguard.

Signed-off-by: Pavel Solodovnikov <2cf5887fafb117b7ff3e29b9720a7305c3313494@scylladb.com>

scylladb/scylla,scylladb/scylla,scylladb/scylla,scylladb/scylla