We run the agent overlay module along with the Master in order to connect the Master node to the overlay. Currently the agent overlay module running on the master creates a docker bridge to
connect any docker containers that might be run on the master in order to connect them to the overlay. However, we never run any docker containers on the overlay, on the Master, thus the docker bridge is redundant and causes an unnecessary dependency for the Master on the docker daemon. Therefore we should be disabling the docker bridge for the agent overlay module on the Master.
Changes merged upstream.