add field for preferred data product variation category

bt5/erp5_wendelin/SkinTemplateItem/portal_skins/erp5_wendelin/WendelinPreference_view.xml

@@ -93,6 +93,7 @@
                     <key> <string>left</string> </key>
                     <value>
                       <list>
+                        <string>my_preferred_data_product_variation_base_category_list</string>
                         <string>my_preferred_data_product_individual_variation_base_category_list</string>
                       </list>
                     </value>