Blender Git Loki

Fix T72083: Object.proxy_collection is been set to linked target object
even when target is not a collection

Looks like this was (accidentally) removed in {rBbe9e469ead22}
https://developer.blender.org/
rBbe9e469ead227aee8d4c29b98a125cf599c5c8bb#change-pFg0VUTAHY2q

This could also result in a missing update in
object_handle_update_proxy, see T72083 for an example.

Thx @Macroni investigating!

Maniphest Tasks: T72083

Differential Revision: https://developer.blender.org/D6651