The registry.ServiceConfig struct in the API types was meant for the
registry configuration on the daemon side; it has variuos fields we
don't use, defines methods for (un)marshaling JSON, and a custom version
of `net.IPNet`, also to (un)marshal JSON.
None of that is needed, so let's change it to a local type, and implement
a constructor (as we now only have "insecure registries" to care
about).
Signed-off-by: Sebastiaan van Stijn <github@gone.nl>
219cfc8b7d