Currently we may start to receive requests before group0 is configured
during boot. If that happens those requests may try to pull schema and
issue raft read barrier which will crash the system because group0 is
not yet available. Workaround it by pretending the raft is disabled in
this case and use non raft procedure. The proper fix should make sure
that storage proxy verbs are registered only after group0 is fully
functional.
Message-Id: <ZGOZkXC/MsiWtNGu@scylladb.com>