Following metrics are now exported by the prometheus exporter to reflect recent
changes on HAProxy :
* haproxy_process_failed_resolutions
* haproxy_process_bytes_out_total
* haproxy_process_spliced_bytes_out_total
* haproxy_process_bytes_out_rate
and
* haproxy_server_unsafe_idle_connections_current
* haproxy_server_safe_idle_connections_current
* haproxy_server_used_connections_current
* haproxy_server_need_connections_current