Comment 7 for bug 1666227

> Similar check is being done in /usr/libexec/os-refresh-config/configure.d/20-os-net-config

Note that approach is deprecated - all os-net-config execution for in-tree t-h-t network config templates is now done via this (which does contain a similar conditional)

https://github.com/openstack/tripleo-heat-templates/blob/master/network/scripts/run-os-net-config.sh#L112

So adding it to the yum update script is reasonable, or we could make os-net-config tolerate an empty config. I'd still like to understand why it's empty tho :)