Fir set RPE from Overview Regression

.. updating the RPE value via the RPE widget on the overview was lost in
   the last commit, this fix reinstates it.

src/Charts/OverviewItems.cpp

@@ -1334,7 +1334,7 @@ void
 RPErating::applyEdit()
 {
     // update the item - if we have one
-    RideItem *item = parent->parent->property("ride").value<RideItem*>();
+    RideItem *item = parent->parent->current;
 
     // did it change?
     if (item && item->ride() && item->getText("RPE","") != value) {

src/Gui/ChartSpace.h

@@ -135,6 +135,9 @@ class ChartSpace : public QWidget
         QGraphicsView *view;
         QFont titlefont, bigfont, midfont, smallfont;
 
+        // the item we are currently showing
+        RideItem *current;
+
         // to get paint device
         QGraphicsView *device() { return view; }
         const QList<ChartSpaceItem*> allItems() { return items; }
@@ -231,7 +234,6 @@ class ChartSpace : public QWidget
 
         bool stale;
         bool configured;
-        RideItem *current;
 };
 
 #endif // _GC_ChartSpace_h