fix weekly summary bug where ride fails to appear

Without this patch, it will occationally be the case that a ride won't appear
in the weekly summary until the ride is itself selected (as opposed to just
selecting some other ride in the same week).

src/MainWindow.cpp

@@ -1085,11 +1085,14 @@ void MainWindow::generateWeeklySummary()
 	int day;
         if (
 	    (item->type() == RIDE_TYPE) &&
-	    (item->ride) &&
 	    ((day = wstart.daysTo(item->dateTime.date())) >= 0) && 
 	    (day < 7)
 	    ) {
 
+            item->htmlSummary(); // generates item->ride
+            if (!item->ride)
+                continue;
+
 	    RideMetric *m;
 	    item->htmlSummary(); // compute metrics
 	    if ((m = item->metrics.value(weeklySeconds->name()))) {