[update] Use default parallelism of 1
[update] Use default parallelism of 1

Docker-DCO-1.1-Signed-off-by: Josh Hawn <josh.hawn@docker.com> (github: jlhawn)

allencloud/swarmkit,alyyousuf7/swarmkit,RenaudWasTaken/swarmkit,allencloud/swarmkit,AliyunContainerService/swarmkit,RenaudWasTaken/swarmkit,sungwonh/swarmkit,dperny/swarmkit-1,docker/swarmkit,alyyousuf7/swarmkit,docker/swarmkit,elifa/swarmkit,deljuven/swarmkit,cheyang/swarmkit,elifa/swarmkit,jlhawn/swarmkit,dperny/swarmkit-1,AliyunContainerService/swarmkit,Noyan759/swarmkit,diogomonica/swarmkit,diogomonica/swarmkit,deljuven/swarmkit,cheyang/swarmkit,fate-grand-order/swarmkit,sungwonh/swarmkit,fate-grand-order/swarmkit,jlhawn/swarmkit,Noyan759/swarmkit