Update ensure()/reconnect() to catch MessagingError

The error handling code that gets connections reset if necessary
caught ConnectionError. It really needs to catch MessagingError,
which ConnectionError inherits from. There are other types of
MessagingErrors that may occur, such as InternalError, and they need
to cause the connection to reset, as well.

This fix has already been merged into oslo.messaging.

Closes-bug: #1303890
Change-Id: Ic5082b74a362ded8b35cbc75cf178fe6e0db62d0
(cherry picked from commit 234f64d608266f43d8856ff98c89ceba6699d752)