Merge pull request #23863 from owncloud/fix_unit_tests

apps/dav/tests/unit/comments/commentsplugin.php

apps/dav/tests/unit/connector/sabre/filesplugin.php

apps/encryption/tests/lib/MigrationTest.php

apps/encryption/tests/lib/crypto/encryptionTest.php

apps/files_sharing/tests/api/share20ocstest.php

tests/core/controller/avatarcontrollertest.php

tests/lib/appframework/db/mappertest.php

tests/lib/notification/notificationtest.php

tests/lib/share20/managertest.php