Ensure we don't access the net when building docs

(Note, this has not been sent upstream)
remove deprecated assert_unicode sqlalchemy attribute

Removing this enables use with sqlalchemy 0.8.0
The deprecation is described upstream at:
http://docs.sqlalchemy.org/en/latest/changelog/changelog_08.html#change-ad44af79c886d1bb283042deb64f9cbe

Change-Id: I305bfdbcd3c3669c41318ea34115624f729b3909
avoid code path causing qpid exchange leaks

Always assume amqp_rpc_single_reply_queue is True,
so that the problematic code path is ignored.
The issue is discussed at https://pad.lv/1178375