Updated openstack/openstack
Project: openstack/oslo.messaging  04cb7223a54af96ac6b93e07d835512a0b3eb512
null
Fix exception deserialiation on Python 3

Builtin exceptions are now in the builtins module, the exceptions module has
been removed.

Fix also the unit test for tracebacks, Unicode representation doesn't start
with "u" prefix anymore (u'...').

Change-Id: I422be457e23066699950c9a3999878ecf65f1b3f