Fix SDK exception parsing
Fix SDK exception parsing

There are cases we are not parsing the SDK exceptions properly. This
patch is an attempt to fix this problem.

Change-Id: I9ba7756587e87b74b66d8b871e16bcf4700603e9

stackforge/python-senlinclient,stackforge/python-senlinclient,openstack/python-senlinclient,openstack/python-senlinclient