* re-add the metrics that were existing prior to this PR, to keep them
for compatibility reasons with existing Grafana panels:
- opencloud_proxy_requests_total
- opencloud_proxy_errors_total
- opencloud_proxy_duration_seconds
* renamed new metric opencloud_proxy_request_total (that contains the
service label) to opencloud_proxy_service_request_total
* renamed new metric opencloud_proxy_duration_seconds (that contains
the service label) to opencloud_proxy_service_duration_seconds
Pascal Bleser
36747cfbdc