This change causes the message sender to block until the messaging
infrastructure (e.g. the broker) assumes ownership of the message (or
fails to accept it). If the message is accepted, then the sender will
either pend for a response (in the case of RPC), or simply return (in
the case of notification). If the message is rejected by the
messaging infrastructure a MessagingException will be raised at the
sender.
Change-Id: I3f4a1ed1c17e18f6d629f16e6b5c99de45b083d6
Closes-Bug: #1377228