restapi: Update VM pool fail with NPE

Need to set the SingleQxlPci when editing pool from Rest.

Bug-Url: https://bugzilla.redhat.com/1006884
Change-Id: I989fdf6816095c4d607c94331f54f4effb10f03e
Signed-off-by: Shahar Havivi <shavivi@redhat.com>