Remove bogus 'unplug' calls from libvirt VIF test

Since the 'get_config' method was introduced to the libvirt
VIF class, separate from the 'plug' method, there is no need
to call the 'unplug' method in the test suite

Blueprint: libvirt-vif-driver
Change-Id: I1c3d055e258117c2657cd72386472dff2e0e08b8
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
Cleanup pyflakes in nova-manage

Also fixes bug 1097830

Change-Id: Id0d73950709b92f39b7ab7a915373ace0b1616ae
Merge "Cleanup pyflakes in nova-manage"
Merge "Remove bogus 'unplug' calls from libvirt VIF test"