[client] fix/proxy close (#2873)

When the remote peer switches the Relay instance then must to close the proxy connection to the old instance.

It can cause issues when the remote peer switch connects to the Relay instance multiple times and then reconnects to an instance it had previously connected to.

relay/server/peer.go

@@ -2,7 +2,7 @@ package server
 
 import (
 	"context"
-	"io"
+	"errors"
 	"net"
 	"sync"
 	"time"
@@ -57,7 +57,7 @@ func (p *Peer) Work() {
 	for {
 		n, err := p.conn.Read(buf)
 		if err != nil {
-			if err != io.EOF {
+			if !errors.Is(err, net.ErrClosed) {
 				p.log.Errorf("failed to read message: %s", err)
 			}
 			return