Timeout, in seconds, to apply when expecting data from the Docker API when performing the docker pull operation. 0 means no time limit, but this is not recommended (if your docker API locks up, some aspects of Jenkins can also lock up).
i.e. you probably want this set to as long as it takes to pull the entire image onto a fresh docker server. e.g. a few minutes.

Note: This overrides the read timeout specified for the cloud, but only for the docker pull operation (as this operation is expected to take longer than most docker operations).