Export picks only the last entity from a multivalue entity reference field

That's partially reverting 09be1f63ff32bbc154f74c7367cb18023f814113.

This one is fixing 09be1f63ff32bbc154f74c7367cb18023f814113 to keep the speed gain. Probably this is the better approach.

Thanks a lot.
I will adjust the patch a bit and commit it.

Automatically closed - issue fixed for 2 weeks with no activity.