InteractionWorkflow.py: remove method which already exist in father class.

product/ERP5Workflow/Document/InteractionWorkflow.py

@@ -406,9 +406,6 @@ class InteractionWorkflow(IdAsReferenceMixin("", "prefix"), Workflow):
   def getStateValueList(self):
     return None
 
-  def getManagedRoleList(self):
-    return sorted(self.getPortalObject().getDefaultModule('acl_users').valid_roles())
-
   def showAsXML(self, root=None):
     if root is None:
       root = Element('erp5')