Revert "ca: Readd WaitGroup to Server"
Revert "ca: Readd WaitGroup to Server"

This reverts commit 6f5c77793f5699383e024c6b2593ffd6d59b8e0e.

Signed-off-by: Aaron Lehmann <8ecfc6017a87905413dcd7d63696a2a4c351b604@docker.com>

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