feat(metrics): add http metrics

modules/metrics/collector.go

@@ -11,10 +11,15 @@ import (
 	"code.gitea.io/gitea/modules/setting"
 
 	"github.com/prometheus/client_golang/prometheus"
+	"github.com/prometheus/common/model"
 )
 
 const namespace = "gitea_"
 
+func init() {
+	model.NameValidationScheme = model.UTF8Validation
+}
+
 // Collector implements the prometheus.Collector interface and
 // exposes gitea metrics for prometheus
 type Collector struct {