added aggregate to group sub_variation

git-svn-id: https://svn.erp5.org/repos/public/erp5/trunk@4818 20353a03-c40f-0410-a6d1-a30d3c3de9de

bt5/erp5_trade/CategoryTemplateItem/portal_categories/aggregate.xml

@@ -54,6 +54,14 @@
               </tuple>
             </value>
         </item>
+        <item>
+            <key> <string>category_type</string> </key>
+            <value>
+              <tuple>
+                <string>sub_variation</string>
+              </tuple>
+            </value>
+        </item>
         <item>
             <key> <string>description</string> </key>
             <value>