Id346bce6e47431988cce7001abcf29a9faf2936a attempted to introduce a
simple breadcrumb in the logs to highlight a known Libvirt issue.
Unfortunately this change resulted in libvirtError exceptions that
didn't match the known issue being silently ignored.
This change corrects this by using excutils.save_and_reraise_exception
to ensure all libvirtError exceptions are logged and raised regardless
of being linked to the known issue.
Change-Id: Ib440f4f2e484312af5f393722363846f6c95b760
Closes-Bug: #1825882
(cherry picked from commit bc57ae5073)
(cherry picked from commit b3dedefcc5)