Do not use Docker for running a Redis server in the test-sim that we
check that Satellite can still operate when Redis is unavailable because
we have to run this test in Jenkins and we don't want to empower a
container to be able to connect to the Docker socket of the host machine
for running sibling containers.
Change-Id: I6180e8ed804968c8ccb0783ed334acab38af9a0f
