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.

--

Cherry-picked from oslo-incubator 234f64d608266f43d8856ff98c89ceba6699d752
See also https://bugzilla.redhat.com/show_bug.cgi?id=1086077

Closes-bug: #1303890
Change-Id: Ic5082b74a362ded8b35cbc75cf178fe6e0db62d0
Merge "Update ensure()/reconnect() to catch MessagingError" into stable/havana