hotfix(dns): always run and use built-in DNS server

- start DNS server before healthcheck
- do not fallback to plaintext anymore
- allow to use plain addresses with a port different than 53, system-wide
- do not wait for the DNS server and rely on healtcheck only

internal/dns/setup.go

@@ -4,7 +4,6 @@ import (
 	"context"
 	"fmt"
 
-	"github.com/qdm12/dns/v2/pkg/check"
 	"github.com/qdm12/dns/v2/pkg/middlewares/filter/update"
 	"github.com/qdm12/dns/v2/pkg/nameserver"
 	"github.com/qdm12/dns/v2/pkg/server"
@@ -44,11 +43,5 @@ func (l *Loop) setupServer(ctx context.Context, settings settings.DNS) (runError
 		l.logger.Error(err.Error())
 	}
 
-	err = check.WaitForDNS(ctx, check.Settings{})
-	if err != nil {
-		l.stopServer()
-		return nil, err
-	}
-
 	return runError, nil
 }