[Tarantool-patches] [PATCH] box: netbox.self and connect should work interchangeably

[Vladislav Shpilevoy]

Thanks for working on this, LGTM.

Here is @ChangeLog for Kirill:
- netbox.self:call/eval() now returns all the same types, as
  netbox_connection:call/eval. Previously it could return
  tuple or box.error cdata (gh-4513).

Since we got 2 LGTMs, I committed the patch to master, 2.3, 2.2,
1.10. The changelog is added to release notes.