"nm-compat.h" is not intended to be used by NetworkManager itself.
Instead, it's intended to be copied into the source tree of VPN plugins,
as adapter for different libnm versions.
Move it to "src/contrib/".
This file is not actually to be used by NetworkManager itself.
Instead, every (glib based) VPN plugin will want something like this,
hence we have a copy here.
Move it to a new directory "src/contrib/".