[ovirt_hosted_engine] fix exception when force-enabled

Fixes #416.

Signed-off-by: Bryn M. Reeves <bmr@redhat.com>
[corosync] add postprocessing for corosync-objctl output

The corosync-objctl command may include fence device passwords in
its output. Remove them with the same postprocessing regex as the
cluster plugin uses.

Signed-off-by: Bryn M. Reeves <bmr@redhat.com>