network_info cache should be cleared before being rescheduled

If an instance fails to boot due to a non-networking error the instance
then gets rescheduled and launched on another compute node. In these cases
deallocate_for_instance() is called which deletes the network ports
allocated though the info_cache for the instance is never cleared. This patch
adds a call to update_instance_cache_with_nw_info() which causes the cache
to get cleared out. Note: the cache is only cleared if the instance hasn't
been marked for deletion. This is due to how instance_info_cache_update()
is implemented.

Change-Id: If967884c9a6276f5949a7a04b597cedcce12ba09
Closes-bug: #1285158
(cherry picked from commit 3538a9cd06e1e46ec5698edf4018c8d3075b619b)
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)
(cherry picked from commit fae88f6805f6a16a60c23da67ce06cc0c78a706d)
Merge "network_info cache should be cleared before being rescheduled" into stable/havana