erp5_trade: display always this field

otherwise, it's not possible to change after add line

bt5/erp5_trade/SkinTemplateItem/portal_skins/erp5_trade/OrderLine_view/my_source_trade_title_list.xml

@@ -9,7 +9,9 @@
         <item>
             <key> <string>delegated_list</string> </key>
             <value>
-              <list/>
+              <list>
+                <string>enabled</string>
+              </list>
             </value>
         </item>
         <item>
@@ -50,6 +52,10 @@
             <key> <string>tales</string> </key>
             <value>
               <dictionary>
+                <item>
+                    <key> <string>enabled</string> </key>
+                    <value> <string></string> </value>
+                </item>
                 <item>
                     <key> <string>field_id</string> </key>
                     <value> <string></string> </value>
@@ -69,6 +75,10 @@
             <key> <string>values</string> </key>
             <value>
               <dictionary>
+                <item>
+                    <key> <string>enabled</string> </key>
+                    <value> <int>1</int> </value>
+                </item>
                 <item>
                     <key> <string>field_id</string> </key>
                     <value> <string>my_view_mode_source_trade_title_list</string> </value>