test: do not race server.close with timeout

Refs: nodejs#43680

Author: mmomtchev

test/parallel/test-http-client-response-timeout.js

@@ -9,6 +9,6 @@ server.listen(common.mustCall(() => {
     http.get({ port: server.address().port }, common.mustCall((res) => {
       res.on('timeout', common.mustCall(() => req.destroy()));
       res.setTimeout(1);
-      server.close();
+      setTimeout(common.mustCall(() => server.close()), 2);
     }));
 }));