jsonrpc: Host_startMonitoringDomain

Align naming between API.py and schema.


Change-Id: Iac1615818be35df18d72cd89dbeae4ebc4e63124
Signed-off-by: pkliczewski <piotr.kliczewski@gmail.com>
Reviewed-on: http://gerrit.ovirt.org/35525
Reviewed-by: Adam Litke <alitke@redhat.com>