Description of problem:
I put a host on maintenance for some days. Actually, I've shut it down and unplugged it temporary.
I found it strange that oVirt was trying to check updates on a host that is clearly not meant to be available.

Version-Release number of selected component (if applicable):
3.6.5

How reproducible:
Always

Steps to Reproduce:
1.Put a host in maintenance
2.Physically unplug it (including its power management cords)
3.Wait, and witness that oVirt is trying to reach it for updates checks

Actual results:
We see this error message :
"Failed to check for available updates on host xxxxxxxxx with message 'Failed to get the session.'."


Expected results:
No update check be done on host on maintenance.