qtdeclarative5-xmllistmodel-plugin is optional on kubuntu

After installing and running third part plasma-widgets ( yahoo weather and weather widget from yr.no) on kubuntu 15.04 I get an error message saying »module "QtQuick.XmlListModel" is not installed«. It is quite simple to solve, but I believe it should be installed on kubuntu by default.

For more information see:
http://kde-apps.org/content/show.php/Yahoo!+Weather+Widget?content=164194
https://forum.qt.io/topic/45916/solved-not-able-to-find-qtquick-xmllistmodel/4