StorageDriver.php $newProperties might not be defined

[tmotyl]

While running phpstan, I'm getting following error:

Line azurestorage/Classes/Driver/StorageDriver.php

---

1180 Variable $newProperties might not be defined.
1183 Variable $newProperties might not be defined.

https://github.com/benjaminhirsch/typo3-azurestorage/blob/master/Classes/Driver/StorageDriver.php#L1180