Under following conditions session affinity leads to a deadlock:
  - Self hosted controller-manager, where it talks to API servers
    via kubernetes service ClusterIP
  - default master-count reconcilier is used
  - --apiserver-count is set to >1 according to the help message
  - number of responsive APIServers goes below `apiserver-count`
  - all controller-managers happen to be hashed to APIServers which
    are down.

What then happens is that controller managers never be able to
contact APIServer, despite correctly working APIServer available.

Less serious outages also possible for other consumers of kubernetes
service, such as operators, kube-dns, flannel & calico, etc.  There is
always non zero chance, that given consumer is hashed  to an apiserver
which is down.

Revert "give the kubernetes service client ip session affinity"
This reverts commit e21ebbca.