Don't set up the L3_EXT_BRIDGE twice
Don't set up the L3_EXT_BRIDGE twice

Change-Id: Ieffc7bc8b5b113ac580292ac43ed158f13db5b43
Resolves: bz#1000981

mahak/packstack,fr34k8/packstack,fr34k8/packstack,xbezdick/packstack,larsks/packstack,larsks/packstack,stackforge/packstack,xbezdick/packstack,mahak/packstack,imcsk8/packstack,openstack/packstack,palmer159/openstack-test,mahak/packstack,fr34k8/packstack,openstack/packstack,stackforge/packstack,larsks/packstack,stackforge/packstack,xbezdick/packstack,palmer159/openstack-test,imcsk8/packstack,imcsk8/packstack,palmer159/openstack-test,openstack/packstack