Make a backward compatible docutils fix
Make a backward compatible docutils fix

THe fix for docutils 0.13 doesn't work with 0.12, obviously. This works
around the issue handling both version of the internal API.

Change-Id: I3bebb206a3205a6f3fa77a7844e50c2e090630a4

noironetworks/heat,openstack/heat,noironetworks/heat,openstack/heat