3rd party component update: Qt Virtual Keyboard

There was related discussion in Qt Contributors Summit. Memo: https://wiki.qt.io/QtCS2018_Third-Party_Sources_Policy_and_Security

1. Check if we need to update some 3rd party components used
2. Check if documentation of 3rd party component usage is correct and do needed updates. Documentation here: http://doc.qt.io/qt-5/licenses-used-in-qt.html
3. In case of 3rd party component update we need to document the update here: http://code.qt.io/cgit/qt/qtdoc.git/tree/doc/src/legal/licensechanges.qdoc

If there are questions, please contact dedicated R&D owner (frederik)