to fix the plasma job notification actions (see the previous commit), also
changing the destination URL type to QString because it is such (see
kdelibs/kio/kio/copyjob.cpp and kdelibs/kio/kio/job.cpp) and the
QVariant/QDBusVariant conversion is redundant
requires changes to the job tracker interface in kdelibs aswell.. see
kdelibs/kdeui/jobs/kuiserverjobtracker.cpp
Signed-off-by: Ivailo Monev <xakepa10@gmail.com>