Use gateway only for 'public' net in bonding test
Use gateway only for 'public' net in bonding test

In system tests for bonding feature we use IP subnet
for public network (/24) for other networks which are
assigned to bonded interface by splitting it on /27
subnets. But we can't use public network router as
gateway for them.

Change-Id: I0291f227cf84f1cdce11c801a044d51f24448654
Closes-bug: #1403007

ddepaoli3/fuel-main-dev,SmartInfrastructures/fuel-main-dev,eayunstack/fuel-main,SmartInfrastructures/fuel-main-dev,teselkin/fuel-main,eayunstack/fuel-main,zhaochao/fuel-main,huntxu/fuel-main,Fiware/ops.Fuel-main-dev,Fiware/ops.Fuel-main-dev,AnselZhangGit/fuel-main,AnselZhangGit/fuel-main,SmartInfrastructures/fuel-main-dev,SergK/fuel-main,Fiware/ops.Fuel-main-dev,AnselZhangGit/fuel-main,stackforge/fuel-main,teselkin/fuel-main,SmartInfrastructures/fuel-main-dev,SergK/fuel-main,stackforge/fuel-main,teselkin/fuel-main,dancn/fuel-main-dev,SergK/fuel-main,stackforge/fuel-main,eayunstack/fuel-main,zhaochao/fuel-main,teselkin/fuel-main,huntxu/fuel-main,dancn/fuel-main-dev,dancn/fuel-main-dev,AnselZhangGit/fuel-main,zhaochao/fuel-main,ddepaoli3/fuel-main-dev,ddepaoli3/fuel-main-dev,zhaochao/fuel-main,huntxu/fuel-main,zhaochao/fuel-main,Fiware/ops.Fuel-main-dev,ddepaoli3/fuel-main-dev,dancn/fuel-main-dev