Revert unintended test expectation change

Commit fbe3059 included an unintended change to the test which checks if
dns_get_record populates its additional parameter. This patch reverts
such change.

The issue was not detected by the CIs because their tests run in
the --offline mode, and the test in question needs internet connection.

Closes GH-9625.

Author: athos-ribeiro

ext/standard/tests/network/bug73594.phpt

@@ -24,4 +24,4 @@ $res = dns_get_record('php.net', DNS_MX, $auth, $additional);
 var_dump(!empty($res) && empty($additional));
 ?>
 --EXPECT--
-bool(true)
+bool(false)