testSetupNetworksAddDelDhcp: Improve readability

Change-Id: Ia373fa3a9399aa05799804e984682fbd5673b004
Signed-off-by: Ondřej Svoboda <osvoboda@redhat.com>
Reviewed-on: http://gerrit.ovirt.org/35983
Reviewed-by: Ido Barkan <ibarkan@redhat.com>
Reviewed-by: Dan Kenigsberg <danken@redhat.com>