engine: add missing sudo in ubuntu instructions
engine: add missing sudo in ubuntu instructions

Looks like the Debian version was updated during review, but the Ubuntu variant
was forgotten in 760bb64ea3cc619e653b6eb0f8d186d6c0a9faa7

Signed-off-by: Sebastiaan van Stijn <64b2b6d12bfe4baae7dad3d018f8cbf6b0e7a044@gone.nl>

docker/docker.github.io,docker/docker.github.io,thaJeztah/docker.github.io,thaJeztah/docker.github.io,thaJeztah/docker.github.io,docker/docker.github.io,docker/docker.github.io,thaJeztah/docker.github.io,thaJeztah/docker.github.io,docker/docker.github.io