pyroute2: unused import removed

Change-Id: I1d404d135f8151eee1c5263fb00da7398ae4ef1c
Signed-off-by: Petr Horáček <phoracek@redhat.com>
Reviewed-on: http://gerrit.ovirt.org/30862
Reviewed-by: Dan Kenigsberg <danken@redhat.com>
Tested-by: Dan Kenigsberg <danken@redhat.com>