Fix a memory leak in KuitStaticData
Summary:
domainSetups QHash was populated in Kuit::setupForDomain, but
the values of the QHash where not deleted in the default destructor.
All the credit goes to mpyne, anthonyfierony, aacid and apol.
Reviewers: Frameworks, dfaure
Reviewed By: dfaure
Tags: Frameworks
Differential Revision: https://phabricator.kde.org/D9156