nova-net: Remove unused exceptions
nova-net: Remove unused exceptions

Not all of these are nova-network related, but all are unused

Change-Id: I6fd027fb51823b8a8a24ed7b864a2191c4e8e8c0
Signed-off-by: Stephen Finucane <492121341a95b3c3aab646bed44634f739dd019b@redhat.com>

mahak/nova,rahulunair/nova,openstack/nova,klmitch/nova,rahulunair/nova,mahak/nova,openstack/nova,openstack/nova,klmitch/nova,mahak/nova,klmitch/nova,rahulunair/nova,klmitch/nova