Avoid going into causes of non-taskflow exceptions
Avoid going into causes of non-taskflow exceptions

Change-Id: If043bf27f3b025a279f3747841e9a88fcc5fab85

junneyang/taskflow,jimbobhickville/taskflow,openstack/taskflow,junneyang/taskflow,jimbobhickville/taskflow,pombredanne/taskflow-1,pombredanne/taskflow-1,openstack/taskflow