[ACS4.4] cherry pick commit 0f755ee4fcb0c2108e87eccea640f50748071050

[Sanjay Tripathi]

Hi Hugo/Daan,

Could you please cherry-pick following commit to 4.4 branch.

Commit: 0f755ee4fcb0c2108e87eccea640f50748071050

CLOUDSTACK-6452: Failed to Live Migrate VM across clusters with Xenserver 
6.2.5'.

--Sanjay