3rd party component update: Qt D-Bus

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

Following actions needs to be done for all Qt modules using 3rd party components

1. Check if we need to update  libdus-1 headers (http://code.qt.io/cgit/qt/qtbase.git/tree/src/dbus/qt_attribution.json)
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

R&D owner: vhilshei