Unbreak FTBFS after recent docker-libkv changes

In the light of #1015218 I started looking at avoiding the dependency on consul. Our version of consul is already quite old and it seems we may be lacking on personell capacity to actively keep the consul package up to standards. Removing the dependencies seems easier.

I've therefore uploaded docker-libkv 0.2.1-3 which breaks the compilation of docker.io.

This MR remedies that.