engine : Upgrading a hypervisor automatically puts it into an Up state

When a host is put in maintenance and is re-installed
even when the host does not require a reboot the
host should go to maintenance.

Change-Id: I6dbe7f492e7202b46f993d6ae3ac14714e39d768
Bug-Url: https://bugzilla.redhat.com/1073070
Signed-off-by: Ravi Nori <rnori@redhat.com>