enh: skip processing for empty response

Signed-off-by: Daniel Kesselberg <mail@danielkesselberg.de>

lib/private/Http/Client/DnsPinMiddleware.php

@@ -25,6 +25,7 @@ declare(strict_types=1);
  */
 namespace OC\Http\Client;
 
+use OCP\Http\Client\LocalServerException;
 use Psr\Http\Message\RequestInterface;
 
 class DnsPinMiddleware {
@@ -127,6 +128,10 @@ class DnsPinMiddleware {
 
 				$targetIps = $this->dnsResolve($hostName, 0);
 
+				if (empty($targetIps)) {
+					throw new LocalServerException('No DNS record found for ' . $hostName);
+				}
+
 				$curlResolves = [];
 
 				foreach ($ports as $port) {