Let client provide a default cluster domain.
Let client provide a default cluster domain.

Old traffic-managers will not report a cluster domain so a default is
needed in the root daemon.

Signed-off-by: Thomas Hallgren <5f50a84c1fa3bcff146405017f36aec1a10a9e38@datawire.io>

datawire/telepresence,datawire/telepresence,datawire/telepresence