core:Power Management or fence errors are not...

Power Management or fence errors are not logged in EVENT tab of GUI.

Adding missing handling in VdsNotRespondingTreatmentCommand::canDoAction
to log the failure as an alert if validation of this command fail as a
result of a PM that was not configured properly.
(Actually removing the "if" that did that only if Host PM is not
configured at all...)

Change-Id: Ic6aac13138c33f2631a1ea424428b4785c1d5700
Signed-off-by: Eli Mesika <emesika@redhat.com>