ERP5Site.py: check portal_workflow is in action provider list after migration.

product/ERP5/ERP5Site.py

@@ -1668,7 +1668,9 @@ class ERP5Site(FolderMixIn, CMFSite, CacheCookieMixin):
       self.portal_workflow = new_tool
       self.portal_workflow.id = 'portal_workflow'
       self._delObject('portal_workflow_new')
-
+      # check action provider list
+      if 'portal_workflow' not in self.portal_actions.listActionProviders():
+        self.portal_actions.addActionProvider('portal_workflow')
 Globals.InitializeClass(ERP5Site)
 
 def getBootstrapDirectory():