The cql_config_updater is a sharded<> service that exists in main and
whose goal is to make sure some db::config's values are propagated into
cql_config. There's a more handy updateable_value<> glue for that.
tests: unit(dev)
refs: #2795
Signed-off-by: Pavel Emelyanov <xemul@scylladb.com>
Message-Id: <20210927090402.25980-1-xemul@scylladb.com>