Disable SwiftDispersion when using docker

We currently have the following in the registry:
OS::TripleO::Services::SwiftDispersion: puppet/services/swift-dispersion.yaml

Since this service is included by default in the Controller role
it will be installed on the host even on a containerized deployment.

Let's noop this in docker.yaml until a containerized version of it
gets merged.

Change-Id: Ic2793d0cfb7b20f4661cb1a45793cae67a4868b4
Closes-Bug: #1723788

environments/docker.yaml

@@ -56,6 +56,9 @@ resource_registry:
   OS::TripleO::Services::CinderApi: ../docker/services/cinder-api.yaml
   OS::TripleO::Services::CinderScheduler: ../docker/services/cinder-scheduler.yaml
   OS::TripleO::Services::CinderVolume: ../docker/services/cinder-volume.yaml
+  # FIXME: Note we explicitely disable SwiftDispersion until a containerized version of it is merged
+  OS::TripleO::Services::SwiftDispersion: OS::Heat::None
+
 
   # If SR-IOV is enabled on the compute nodes, it will need the SR-IOV
   # host configuration.