do not call generateNewId if the subscriber alreasy has an id

git-svn-id: https://svn.erp5.org/repos/public/erp5/trunk@3135 20353a03-c40f-0410-a6d1-a30d3c3de9de

product/ERP5SyncML/Publication.py

@@ -196,6 +196,8 @@ class Publication(Subscription):
     """
     # We have to remove the subscriber if it already exist (there were probably a reset on the client)
     self.delSubscriber(subscriber.getSubscriptionUrl())
+    new_id = subscriber.getId()
+    if new_id is None:
       new_id = str(self.generateNewId())
     subscriber.id = new_id
     #if len(self.list_subscribers) == 0: