[Neutron] Don't run fwaas/lbaas classes on standalone api nodes
[Neutron] Don't run fwaas/lbaas classes on standalone api nodes

With patch https://review.openstack.org/#/c/200877/ lbaas/fwaas
packages will be installed in ::neutron class and it's not necessary
to set up whole agents/services on the api node.

Change-Id: I89c32cd69d3ad06ed04460ded64deb7faeec3712
Closes-Bug: rhbz#1233149

mahak/packstack,openstack/packstack,imcsk8/packstack,fr34k8/packstack,xbezdick/packstack,stackforge/packstack,stackforge/packstack,mahak/packstack,xbezdick/packstack,openstack/packstack,xbezdick/packstack,imcsk8/packstack,fr34k8/packstack,imcsk8/packstack,fr34k8/packstack,stackforge/packstack,openstack/packstack,mahak/packstack