Pull request: 3914 fix lack of client name

Merge in DNS/adguard-home from 3914-fix-client-name to master

Closes #3914.

Squashed commit of the following:

commit 6bd06d277ec5e64fc548245eee75edd8da67fa2c
Author: Eugene Burkov <E.Burkov@AdGuard.COM>
Date:   Fri Dec 3 17:13:15 2021 +0300

    dnsforward: fix lack of client name

internal/dnsforward/clientid.go

@@ -2,7 +2,6 @@ package dnsforward
 
 import (
 	"crypto/tls"
-	"encoding/binary"
 	"fmt"
 	"path"
 	"strings"
@@ -172,19 +171,3 @@ func (s *Server) clientIDFromDNSContext(pctx *proxy.DNSContext) (clientID string
 
 	return clientID, nil
 }
-
-// processClientID puts the clientID into the DNS context, if there is one.
-func (s *Server) processClientID(dctx *dnsContext) (rc resultCode) {
-	pctx := dctx.proxyCtx
-
-	var key [8]byte
-	binary.BigEndian.PutUint64(key[:], pctx.RequestID)
-	clientIDData := s.clientIDCache.Get(key[:])
-	if clientIDData == nil {
-		return resultCodeSuccess
-	}
-
-	dctx.clientID = string(clientIDData)
-
-	return resultCodeSuccess
-}