TD: Use new-style syntax of connect()

When fixing clazy issues -Wclazy-fully-qualified-moc-types then old-style syntax of connect() may fail. Thus, replace it with the new-style syntax

src/Mod/TechDraw/Gui/TaskLeaderLine.cpp

@@ -613,8 +613,8 @@ void TaskLeaderLine::startTracker(void)
     if (!m_tracker) {
         m_tracker = new QGTracker(m_scene, m_trackerMode);
         QObject::connect(
-            m_tracker, SIGNAL(drawingFinished(std::vector<QPointF>, QGIView*)),
-            this     , SLOT  (onTrackerFinished(std::vector<QPointF>, QGIView*))
+            m_tracker, &QGTracker::drawingFinished,
+            this     , &TaskLeaderLine::onTrackerFinished
            );
     } else {
         //this is too harsh. but need to avoid restarting process