stork-agent: Encountered unsupported stat

name: Bug report
about: stork-agent Encountered unsupported stat

Describe the bug When enabling prometheus output I get errors in the log and no data in grafana:

Aug 16 10:43:39 rover stork-agent[56760]: time="2022-08-16 10:43:39" level="info" msg="Encountered unsupported stat: cumulative-assigned-addresses" file="  promkeaexporter.go:683  "
Aug 16 10:43:39 rover stork-agent[56760]: time="2022-08-16 10:43:39" level="info" msg="Encountered unsupported stat: reclaimed-declined-addresses" file="  promkeaexporter.go:683  "
Aug 16 10:43:39 rover stork-agent[56760]: time="2022-08-16 10:43:39" level="info" msg="Encountered unsupported stat: declined-addresses" file="  promkeaexporter.go:683  "
Aug 16 10:43:39 rover stork-agent[56760]: time="2022-08-16 10:43:39" level="info" msg="Encountered unsupported stat: reclaimed-leases" file="  promkeaexporter.go:683  "

To Reproduce Steps to reproduce the behavior: Stork 1.5.0 with config:

STORK_AGENT_LISTEN_PROMETHEUS_ONLY=true
STORK_AGENT_PROMETHEUS_KEA_EXPORTER_ADDRESS= 127.0.0.1
STORK_AGENT_PROMETHEUS_KEA_EXPORTER_INTERVAL= 60
STORK_AGENT_PROMETHEUS_KEA_EXPORTER_PER_SUBNET_STATS=true
STORK_AGENT_SKIP_TLS_CERT_VERIFICATION=true

Expected behavior Data should be be properly scraped from the kea api and exposed via prometheus.

Environment: Kea version info:

# kea-dhcp4 -V
2.0.1
tarball
linked with:
log4cplus 1.1.2
OpenSSL 1.1.1n  15 Mar 2022
database:
MySQL backend 12.0, library 10.3.34
PostgreSQL backend 6.2, library 110016
Memfile backend 2.1

Using the following hooks:

"hooks-libraries": [
    
    {
        "library": "/usr/lib/x86_64-linux-gnu/kea/hooks/libdhcp_lease_cmds.so",
        "parameters": { }
    },

    {
        "library": "/usr/lib/x86_64-linux-gnu/kea/hooks/libdhcp_stat_cmds.so",
        "parameters": { }
    },

    {
        "library": "/usr/lib/x86_64-linux-gnu/kea/hooks/libdhcp_ha.so",
        "parameters": {
            "high-availability": [
		{
                    "this-server-name": "rover",
                    "mode": "hot-standby",
                    "heartbeat-delay": 2000,
                    "max-response-delay": 12000,
                    "max-ack-delay": 10000,
                    "max-unacked-clients": 0,

		    "multi-threading": {
                        "enable-multi-threading": true,
                        "http-dedicated-listener": true,
                    },

                    "peers": [
			{
			    "name": "rover",
			    "role": "primary",
			    "auto-failover": true
			}, {
			    "name": "spot",
			    "role": "standby",
			    "auto-failover": true
			}
		    ]
		}
	    ]
        }
    }
]