Qubes manager used different logic what it considers as "running VM",
than qubes core.
Here it was "running or starting/stopping", while qubes core uses the
same as libvirt (isActive()), which effectively means "not halted" -
which includes also "paused" and "suspended". This creates a lot
confusion in which action should be available when.
The actual detected bug was about resuming paused VM. There was assert
"not vm.is_running()", while the paused VM _is_ running in terms of
qubes core.
Fixesqubesos/qubes-issues#981
