fix the condition that is always True.

git-svn-id: https://svn.erp5.org/repos/public/erp5/trunk@34173 20353a03-c40f-0410-a6d1-a30d3c3de9de

product/ERP5Type/Tool/SessionTool.py

@@ -234,7 +234,7 @@ class SessionTool(BaseTool):
   def manage_delObjects(self, ids=[], REQUEST=None):
     """ Delete session object. """
     storage_plugin = self._getStoragePlugin()
-    if not isinstance(ids, list) or isinstance(ids, list):
+    if not isinstance(ids, (list, tuple)):
       ids = [ids]
     for session_id in ids:
       storage_plugin.delete(session_id, SESSION_SCOPE)