[PC][MP] Stealing other farm's harvest

[tim260]

- PC/Mac/PS4/XB1: Probably happening on all platforms
- Vehicle/Tool/Model/Object: Joskin trailer with a NH T6 but will work with any trailers
- Issue: Stealing other farms their harvest
- Single- or Multiplayer: MP (Multiple farms)
- Steps to reproduce: Get another farm to toggle a helper harvesting, You as other farm drive on the unload path and receive the harvest ( No need to toggle contractor )
- Does it happen on a standard map without mods yes/no: yes