Requests to docker daemon fail after curl update

[csmith]

It seems that curl 7.5x changed how URLs were handled for unix sockets, which prevents the kill request used in init.sh from succeeding (the docker daemon responds instead with a 404).

There's some discussion around the change at moby/moby#17960 (comment), but briefly in older versions of curl http:/containers/xyz resulted in a request for /containers/xyz, and in newer versions it results in a Host: containers header and a request for /xyz

[kquinsland]

I was just bit by this as well on docker 18.09 / API version 1.39.

the cURL path has changed, apparently.