Prevent stylesheet inheritance for active render window widgets
Summary:
This was already partially done in fbc49fc5c831 but needed to be done
as well inside the QmitkMxNMultiWidget for active render window widgets.
Test Plan:
manual:
- open QmitkStdMultiWidget and QmitkMxNMultiWidget
- compare render window menu border (thickness / color)
-> they should be the same
Reviewers: kislinsk, O3 MITK Reviewer Group II
Reviewed By: kislinsk, O3 MITK Reviewer Group II
Subscribers: kalali
Maniphest Tasks: T24672
Differential Revision: https://phabricator.mitk.org/D539