fixup! erp5_tiosafe_core: add property to hold the exchange format version

bt5/erp5_tiosafe_core/PropertySheetTemplateItem/portal_property_sheets/IntegrationSite.xml

@@ -13,11 +13,17 @@
             </value>
         </item>
         <item>
-            <key> <string>_tree</string> </key>
+            <key> <string>_mt_index</string> </key>
             <value>
               <persistent> <string encoding="base64">AAAAAAAAAAM=</string> </persistent>
             </value>
         </item>
+        <item>
+            <key> <string>_tree</string> </key>
+            <value>
+              <persistent> <string encoding="base64">AAAAAAAAAAQ=</string> </persistent>
+            </value>
+        </item>
         <item>
             <key> <string>description</string> </key>
             <value>
@@ -45,4 +51,12 @@
       <none/>
     </pickle>
   </record>
+  <record id="4" aka="AAAAAAAAAAQ=">
+    <pickle>
+      <global name="OOBTree" module="BTrees.OOBTree"/>
+    </pickle>
+    <pickle>
+      <none/>
+    </pickle>
+  </record>
 </ZopeData>