Fix documentation wrong metric type

[averevki]

# HELP auth_server_authconfig_duration_seconds Response latency of authconfig enforced by the auth server (in seconds).
# TYPE auth_server_authconfig_duration_seconds histogram
auth_server_authconfig_duration_seconds_bucket{authconfig="test",namespace="test-ns",le="0.001"} 0
auth_server_authconfig_duration_seconds_bucket{authconfig="test",namespace="test-ns",le="0.051000000000000004"} 1
auth_server_authconfig_duration_seconds_bucket{authconfig="test",namespace="test-ns",le="0.101"} 1
auth_server_authconfig_duration_seconds_bucket{authconfig="test",namespace="test-ns",le="0.15100000000000002"} 1
auth_server_authconfig_duration_seconds_bucket{authconfig="test",namespace="test-ns",le="0.201"} 1
auth_server_authconfig_duration_seconds_bucket{authconfig="test",namespace="test-ns",le="0.251"} 1

[guicassolato]

Thanks!