chart2: fix obvious mis-use of wrong member in XMLFilter::impl_Import()

... so we get a BaseURI set.

Change-Id: I01176a8a0b0a1f4386f4d58bdf36bd5cb29cf3e5
(cherry picked from commit 45300b43)

chart2/source/model/filter/XMLFilter.cxx

@@ -364,7 +364,8 @@ sal_Int32 XMLFilter::impl_Import(
 
         // Set base URI and Hierarchical Name
         OUString aHierarchName, aBaseUri;
-        uno::Reference< frame::XModel > xModel( m_xSourceDoc, uno::UNO_QUERY );
+        // why retrieve this from the model when it's availabe as rMediaDescriptor?
+        uno::Reference<frame::XModel> const xModel(m_xTargetDoc, uno::UNO_QUERY);
         if( xModel.is() )
         {
             uno::Sequence< beans::PropertyValue > aModProps = xModel->getArgs();