fix double delete on loading ooo123605-1.odt

if there are no listeners to send the event to then don't
acquire and release the Source in the temporary used by forEach
and so avoid double-releasing on loading ooo123605-1.odt

Change-Id: I6843042d7cf8c0ffee01c7d519299fcb05b29a4e

sw/source/core/unocore/unotbl.cxx

@@ -109,6 +109,8 @@ using ::editeng::SvxBorderLine;
 static void lcl_SendChartEvent(::cppu::OWeakObject & rSource,
                                ::cppu::OInterfaceContainerHelper & rListeners)
 {
+    if (!rListeners.getLength())
+        return;
     //TODO: find appropriate settings of the Event
     chart::ChartDataChangeEvent event;
     event.Source = & rSource;