knowledge_pad: avoid display of istbox_link field in worklist gadget

bt5/erp5_knowledge_pad/SkinTemplateItem/portal_skins/erp5_gadget/ERP5Site_viewWorklistGadget.xml

@@ -2,7 +2,7 @@
 <ZopeData>
   <record id="1" aka="AAAAAAAAAAE=">
     <pickle>
-      <global name="ERP5Form" module="Products.ERP5Form.Form"/>
+      <global name="ERP5 Form" module="erp5.portal_type"/>
     </pickle>
     <pickle>
       <dictionary>
@@ -88,7 +88,9 @@
                 <item>
                     <key> <string>hidden</string> </key>
                     <value>
-                      <list/>
+                      <list>
+                        <string>listbox_link</string>
+                      </list>
                     </value>
                 </item>
                 <item>