AMQP 1.0 - create only one Cyrus SASL configuration for the tests
AMQP 1.0 - create only one Cyrus SASL configuration for the tests

The Cyrus SASL library can only be initialized once per process. And
the configuration must remain available until all the tests have run.

Change-Id: I2810ecf53956fc5d4fcdc944f8e06237ca985e6a
Closes-Bug: #1591211

ozamiatin/oslo.messaging,ozamiatin/oslo.messaging