Internal shipment from_location domain should be child_of

Since there is assignation on internal shipment the from_location could be any
children of main location.

issue3994
review13361002
(grafted from fee63d5cce02d626bdc19d06829989f46b2d6a35)

--HG--
branch : 2.8
extra : source : fee63d5cce02d626bdc19d06829989f46b2d6a35