devenv: switch OpenTSDB docker block (#17849)
devenv: switch OpenTSDB docker block (#17849)

old docker image, https://hub.docker.com/r/opower/opentsdb/,  seems to be gone
grafana/grafana,grafana/grafana,grafana/grafana,grafana/grafana,grafana/grafana,grafana/grafana,grafana/grafana