Missing course acls in OC studio upload

[dennis531]

Version
master branch

Describe the bug
Course acls are not set for OC Studio uploads in a course. There seems to be a race condition in

studip-opencast-plugin/bootstrap.php

Lines 24 to 25 in d206223

	NotificationCenter::addObserver('Opencast\Models\Videos', 'checkEventACL', 'OpencastVideoSync');
	NotificationCenter::addObserver('Opencast\Models\Videos', 'addToCoursePlaylist', 'OpencastVideoSync');

The cronjob "Opencast - Synchronisiert ACLs für Events" is disabled on my system, so it won't fix it.

To Reproduce
Steps to reproduce the behavior:

1. Upload a video via oc studio in a course
2. Wait until the video is available
3. Enter course as student
4. Open video
5. See that user has no permission on this video