Fixes #801 libxml_disable_entity_loader() is changed

[philipp-kolesnikov]

- [x] a bugfix
- [ ] a new feature

Checklist:

• Changes are covered by unit tests
• Code style is respected
• Commit message explains why the change is made (see https://github.com/erlang/otp/wiki/Writing-good-commit-messages)
• CHANGELOG.md contains a short summary of the change
• Documentation is updated as necessary

Why this change is needed?

#802 already provides fix for #801, but scenario like this:

$reader = new \PhpOffice\PhpSpreadsheet\Reader\Xlsx();

libxml_use_internal_errors(true);
libxml_clear_errors();

$document = new DOMDocument();
$document->load("test.xml");

echo libxml_get_last_error()->message. "\n";

will still fail. This PR will fix both issues.

[PowerKiKi]

Merged in 8918888