Summary improvements

* #9424 Show vector name in curve names when history vector is present
* #9426 Curve Legend disappears when curve is unchecked
* Remove duplicate call to visibilityChanged
* Remove unused code

ApplicationLibCode/UserInterface/RiuQwtPlotLegend.h

@@ -35,7 +35,4 @@ signals:
 
 private:
     void deleteAll();
-
-private:
-    int m_columnCount;
 };