taskview: actually corrected taskviewitem order

An earlier commit addressed faulty TaskViewItem ordering by changing
insertWidget to addWidget. Turns out this was the wrong strategy since the
insert was used to get widgets above the stretch. The correct strategy is
using insert(count()-1) instead of insert(0)

app/widget/taskview/taskview.cpp

@@ -44,5 +44,5 @@ TaskView::TaskView(QWidget* parent) :
 void TaskView::AddTask(Task *t)
 {
   // Create TaskViewItem (UI representation of a Task) and connect it
-  layout_->addWidget(new TaskViewItem(t));
+  layout_->insertWidget(layout_->count()-1, new TaskViewItem(t));
 }