Engine: When creating template, target domain is passed as a source

patch: 083eb0820b88d40f40f19006f97cfc580b84d4a6
override the source image storage domain with the destination domain id.

Change-Id: I523814cd3c1f64c1ae40624ba50f239f2cebaed7
Signed-off-by: Shahar Havivi <shavivi@redhat.com>