Similar to 323fbc485e - this code was added
in [moby@c127d96], but used string-matching to detect cases where a user
tried to install an image as plugin. However, this handling no longer matched
any error-strings, so no longer worked:
docker plugin install busybox
Error response from daemon: did not find plugin config for specified reference docker.io/library/busybox:latest
[moby@c127d96]: c127d9614f
Signed-off-by: Sebastiaan van Stijn <github@gone.nl>
fb3f2da50e