Disable creation of cbr0, the kubelet does it now.

Conditionalize the docker bridge.

cluster/saltbase/salt/docker/init.sls

@@ -48,11 +48,6 @@ net.ipv4.ip_forward:
   sysctl.present:
     - value: 1
 
-cbr0:
-  container_bridge.ensure:
-    - cidr: {{ grains['cbr-cidr'] }}
-    - mtu: 1460
-
 {{ environment_file }}:
   file.managed:
     - source: salt://docker/docker-defaults
@@ -124,7 +119,6 @@ docker:
     - enable: True
     - watch:
       - file: {{ environment_file }}
-      - container_bridge: cbr0
 {% if override_docker_ver != '' %}
     - require:
       - pkg: lxc-docker-{{ override_docker_ver }}