speedwidget class: excess QtConcurent usage removal

src/gui/properties/speedwidget.h

@@ -31,7 +31,6 @@
 
 #include <QWidget>
 #include <QComboBox>
-#include <QtConcurrentRun>
 
 #include "speedplotview.h"
 
@@ -64,12 +63,11 @@ public:
 private slots:
     void onPeriodChange(int period);
     void onGraphChange(int id);
+    void update();
 
 private:
-    void update();
     void loadSettings();
     void saveSettings() const;
-    Q_INVOKABLE void graphUpdate();
 
     QVBoxLayout *m_layout;
     QHBoxLayout *m_hlayout;
@@ -81,9 +79,6 @@ private:
     QMenu *m_graphsMenu;
     QList<QAction *> m_graphsMenuActions;
     QSignalMapper *m_graphsSignalMapper;
-
-    QFuture<void> m_updateFuture;
-    bool m_isUpdating;
 };
 
 #endif // SPEEDWIDGET_H