Don't set cell value in wxDataViewEvent in one place only.

We should either set the cell value in the event object everywhere or not do
it anywhere and as currently the native GTK and OS X versions don't do it at
all and the generic version only does it for ITEM_CONTEXT_MENU events, it's
easier to not do it at all.

See #14163.

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@73623 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775

src/generic/datavgen.cpp

@@ -4000,10 +4000,6 @@ void wxDataViewMainWindow::OnMouse( wxMouseEvent &event )
             le.SetItem( item );
             le.SetColumn( col->GetModelColumn() );
             le.SetDataViewColumn( col );
-
-            wxVariant value;
-            model->GetValue( value, item, col->GetModelColumn() );
-            le.SetValue(value);
         }
 
         parent->ProcessWindowEvent(le);