Updated openstack/openstack
Project: openstack/heat  d3af94931657d9bd785e4b6f1ec7989694578788

Refactor UpdateReplace exception

Use six.text_type to format error message, so that we can avoid
possible failure in unittest when switching to oslo.i18n.

Change-Id: I6979a3298ff5c3dac734bd7ad5534853bab1a7d8