Fix fetch response in prepareDataProto.
Fix fetch response in prepareDataProto.

Looks like a logic regression bug.  Before the introduction of the new
protocol version, it checked if there was no result only after all
targets had been looked up.

deniszh/go-carbon,lomik/go-carbon,lomik/go-carbon,deniszh/go-carbon,deniszh/go-carbon,lomik/go-carbon