engine: Multiple gateways test failure fixed

Fixed failing junit tests
1)  at org.junit.Assert.assertFalse(Assert.java:79)
        at org.ovirt.engine.core.bll.SetupNetworksParametersTest.validateParameters(SetupNetworksParametersTest.java:37)

2) NPE in gatewayChanged(org.ovirt.engine.core.bll.network.host.SetupNetworksHelperTest)

Change-Id: Ie0f697a198b064dabc603f3ec438d5ea670b474e
Signed-off-by: Sahina Bose <sabose@redhat.com>