Simplify testAddVlanedBridgeless

There is no need for the networks dictionary.

Change-Id: I8ce6d31d4a0bf7145b1d929939de90063c066828
Signed-off-by: ibarkan <ibarkan@redhat.com>
Reviewed-on: http://gerrit.ovirt.org/36003
Reviewed-by: Ondřej Svoboda <osvoboda@redhat.com>
Reviewed-by: Dan Kenigsberg <danken@redhat.com>