Currently, IPAM config is never validated by the API. Some checks
are done by the CLI, but they're not exhaustive. And some of these
misconfigurations might be caught early by libnetwork (ie. when the
network is created), and others only surface when connecting a container
to a misconfigured network. In both cases, the API would return a 500.
Although the `NetworkCreate` endpoint might already return warnings,
these are never displayed by the CLI. As such, it was decided during a
maintainer's call to return validation errors _for all API versions_.
Signed-off-by: Albin Kerouanton <albinker@gmail.com>
Signed-off-by: Sebastiaan van Stijn <github@gone.nl>