Enhancement: Update SDK to v3.1.0-alpha.3

We updated the ownCloud SDK to version v3.1.0-alpha.3. Please refer to the full changelog in the SDK release (linked) for more details. Summary:

* Bugfix - Allow removing expiration dates from space shares: [owncloud/owncloud-sdk#1204](https://github.com/owncloud/owncloud-sdk/pull/1204)
* Enhancement - Resource processing: [owncloud/owncloud-sdk#1109](https://github.com/owncloud/owncloud-sdk/pull/1109)
* Enhancement - Share space with group: [owncloud/owncloud-sdk#1207](https://github.com/owncloud/owncloud-sdk/pull/1207)


https://github.com/owncloud/web/pull/8320
https://github.com/owncloud/web/pull/8248
https://github.com/owncloud/owncloud-sdk/releases/tag/v3.1.0-alpha.3
