Bugfix: Fix empty settings values

We've updated owncloud-sdk to version 1.0.0-638 which makes sure that an empty array gets returned
whenever there are no settings values for the authenticated user. Previously having no settings
values broke our detection of whether settings values finished loading.

https://github.com/owncloud/web/pull/3602
https://github.com/owncloud/ocis-settings/issues/24
