[#39] ir: Do not store config keys in httpComponent

Pprof will have specific options, it seems wrong to have them in a
generic struct.

Signed-off-by: Evgenii Stratonikov <e.stratonikov@yadro.com>

cmd/frostfs-ir/metrics.go

@@ -4,18 +4,9 @@ import (
 	"git.frostfs.info/TrueCloudLab/frostfs-node/pkg/metrics"
 )
 
-const (
-	prometheusEnabledKey         = "prometheus.enabled"
-	prometheusAddressKey         = "prometheus.address"
-	prometheusShutdownTimeoutKey = "prometheus.shutdown_timeout"
-)
-
 func newMetricsComponent() *httpComponent {
 	return &httpComponent{
-		name:               "prometheus",
-		enabledKey:         prometheusEnabledKey,
-		addressKey:         prometheusAddressKey,
-		shutdownTimeoutKey: prometheusShutdownTimeoutKey,
-		handler:            metrics.Handler(),
+		name:    "prometheus",
+		handler: metrics.Handler(),
 	}
 }