Comment 3 for bug 2012044

Patches welcome on this if we don't get to it soon enough, the upstream code that represents this file is here[1]
The postinstall logic will either need to be a bit smarter in to either early return from disable_network_config_on_upgrade if [ -z ${oldver} ]. Or disable_network_config_on_upgrade should probably only be invoked within a scope of a conditional like `if [ "$1" = "upgrade" ]; then` instead or `if [ "$1" = "configure" ]; then`

We can happily help steer folks to a improve out postinst here if so desired.
Our contributing docs are here[2]

references:
[1] https://github.com/canonical/cloud-init/blob/ubuntu/devel/debian/cloud-init.postinst
[2] https://cloudinit.readthedocs.io/en/latest/development/contributing.html#contributing