Nonexistent quota can be set
Description of problem:
In Hammer, I can specify anything in --ovirt-quota, even if quota with that ID doesn't actually exist.
When viewing the CR in WebUI, the first quota in the list of existing quotas is shown. However, when trying to create a host on that CR, you get the following error in WebUI and a quite useless traceback: "Failed to create a compute testrhevH1 (RHV) instance glen-krick.example.com: HTTP response code is 404. The response body is empty. "
Steps to Reproduce:
1. # hammer compute-resource update --name <current_CR_name> --ovirt-quota <nonexistent_quota_id>
2. In WebUI, try to create a host on the CR
In the database, there are entries with the nonexistent quota.
The hammer command should have failed in the first place.
This is only well debuggable using RHEV's log files.