Updated openstack/openstack
Project: openstack/taskflow  d9124dc47d38b0cc7448802661c98ca8e7bb0651

Handle the case where '_exc_type_names' is empty

If '_exc_type_names' is empty we want to avoid having a
index error or type error and want to handle just not writing
out the first exception type name and instead just write
out the exception text string.

Change-Id: I29fd740fd7052f73975d84ec03455170c420ca89