Disabling ICU
Summary: It is assumed that ICU is not available, which automatically disables this options. This causes problems if another ICU version is found somewhere, e.g. by Anaconda. In this case the build fails.
Test Plan: Coevred by current tests since ICU was disabled in most cases anyway until now.
Reviewers: O1 MITK Core, kislinsk
Reviewed By: O1 MITK Core, kislinsk
Maniphest Tasks: T26438
Differential Revision: https://phabricator.mitk.org/D204