e2e: retry on "connect: connection refused" errors
e2e: retry on "connect: connection refused" errors

Sometimes there are failures in the e2e suite when connecting to the
etcdserver fails. The following error was caught:

    INFO: Error getting pvc "rbd-pvc" in namespace "rbd-1318": Get "https://192.168.39.222:8443/api/v1/namespaces/rbd-1318/persistentvolumeclaims/rbd-pvc": dial tcp 192.168.39.222:8443: connect: connection refused
    FAIL: failed to create PVC with error failed to get pvc: Get "https://192.168.39.222:8443/api/v1/namespaces/rbd-1318/persistentvolumeclaims/rbd-pvc": dial tcp 192.168.39.222:8443: connect: connection refused

If etcdserver was only briefly unavailable, one or more retries might be
sufficient to have the test pass.

Signed-off-by: Niels de Vos <7bda0c0ee7f47171cc808e9e60292cbc5d8140dd@redhat.com>

ceph/ceph-csi,ceph/ceph-csi,ceph/ceph-csi,ceph/ceph-csi