This reverts commit 94c0f6c9d3.
Kpackagekit is not so nice-behaving as gpk-update-viewer is,
e.g. it complains there are is no network connectivity, and, perhaps
as a result, doesn't display the list of avilable updates.
Additionally synchronize clock every 6h. This is started by xdg-autostart (not
qvm-core) to have running Xorg - needed to prompt user for updates download.