only create one observer redis client; fix selected_db prefixing
only create one observer redis client; fix selected_db prefixing

k-components/k-livedb,nmai/livedb,share/livedb,dialoghq/livedb,jclem/livedb,bsnote/livedb,mcanthony/livedb,matthewbauer/livedb,mattbrun/livedb