Description of problem:

After node registration, approve host fails with an error to move host to maintenance while the button is disabled

2017-03-28 12:32:18,842Z INFO  [org.ovirt.engine.core.bll.hostdeploy.RegisterVdsQuery] (default task-28) [dcf06e4] RegisterVdsQuery::register - Registered a new VDS 'pending approval' - Name: 'vdsm-kube-ds-q42jm', Hostname: '172.17.0.2', UniqueID: 'F55AF2C3-89A8-4A9E-BCCE-975F983BDE5E'
2017-03-28 12:32:18,844Z INFO  [org.ovirt.engine.core.dal.dbbroker.auditloghandling.AuditLogDirector] (default task-28) [dcf06e4] EVENT_ID: VDS_REGISTER_SUCCEEDED(828), Correlation ID: null, Call Stack: null, Custom Event ID: -1, Message: Host vdsm-kube-ds-q42jm registered.
2017-03-28 12:32:46,834Z WARN  [org.ovirt.engine.core.bll.hostdeploy.UpdateVdsCommand] (default task-4) [c929dff7-e8df-499e-b03f-43fea611d327] Validation of action 'UpdateVds' failed for user admin@internal-authz. Reasons: VAR__ACTION__UPDATE,VAR__TYPE__HOST,VDS_STATUS_NOT_VALID_FOR_UPDATE
Version-Release number of selected component (if applicable):


How reproducible:
100%


Steps to Reproduce:
1. register new node
2. try to approve
3.

Actual results:
fail


Expected results:
approve command should start host-deploy flow using engine's public key for the ssh communication.