lib/netutil: ignore arificial timeout generated by net/http.Server

This prevents from the inflated vm_tcplistener_read_timeouts_total counter

lib/netutil/conn.go

@@ -7,6 +7,7 @@ import (
 	"net"
 	"sync/atomic"
 
+	"github.com/VictoriaMetrics/VictoriaMetrics/lib/fasttime"
 	"github.com/VictoriaMetrics/metrics"
 )
 
@@ -54,13 +55,19 @@ type statConn struct {
 }
 
 func (sc *statConn) Read(p []byte) (int, error) {
+	startTime := fasttime.UnixTimestamp()
 	n, err := sc.Conn.Read(p)
 	sc.cm.readCalls.Inc()
 	sc.cm.readBytes.Add(n)
 	if err != nil && err != io.EOF {
 		var ne net.Error
 		if errors.As(err, &ne) && ne.Timeout() {
-			sc.cm.readTimeouts.Inc()
+			if fasttime.UnixTimestamp()-startTime <= 1 {
+				// Ignore artificial timeout generated by net/http.Server
+				// See https://cs.opensource.google/go/go/+/refs/tags/go1.20.5:src/net/http/server.go;l=701
+			} else {
+				sc.cm.readTimeouts.Inc()
+			}
 		} else {
 			sc.cm.readErrors.Inc()
 		}