all: Use context in lib/dialer (#6177)

* all: Use context in lib/dialer

* a bit slimmer

* https://github.com/syncthing/syncthing/pull/5753

* bot

* missed adding debug.go

* errors.Cause

* simultaneous dialing

* anti-leak

cmd/strelaypoolsrv/main.go

@@ -7,6 +7,7 @@ package main
 import (
 	"bytes"
 	"compress/gzip"
+	"context"
 	"crypto/tls"
 	"encoding/json"
 	"flag"
@@ -480,7 +481,7 @@ func handleRelayTest(request request) {
 	if debug {
 		log.Println("Request for", request.relay)
 	}
-	if !client.TestRelay(request.relay.uri, []tls.Certificate{testCert}, time.Second, 2*time.Second, 3) {
+	if !client.TestRelay(context.TODO(), request.relay.uri, []tls.Certificate{testCert}, time.Second, 2*time.Second, 3) {
 		if debug {
 			log.Println("Test for relay", request.relay, "failed")
 		}