Example.org no longer serves blank responses, failing functional tests

Problem:

$upload->remote_upload('http://example.com/image.jpg');
expects error EMPTY_REMOTE_DATA, but gets URL_NOT_FOUND instead

Reproduce steps:

1. Run functional tests

Failing test:

phpbb_functional_fileupload_remote_test -> test_non_existant

Proposed solution:

Make a blank file and serve it locally during the test, instead of hitting the http://example.org servers kindly provided by IANA.

Other work that could be done:

In my opinion, no phpbb test should hit an example.org/com/net (or any external) server since a local test server is already running during functional test.