Issue description
When having a train-network with multiple stations and there are for a given good multiple providers and a consumer, when the consumer makes a "pull" request due to the "trains keep full if under X" slider, the request is fulfilled by a random provider station, regardless of any potential priority that is set at the provider stations.

This only occurs if the providers do not have a proactive "empty me" mode active(the red slider). If the providers actively try to get rid of their inventory, the priority system is observed.
I would expect that even without having "push" settings active that deliveries take the priority into account.
Reproduction steps
Load the attached Save
alternatively (easiest in Sandbox)
- Have a train-network with 3 stations all dedicated to the same good and one train that is capable of transfering that good.(All stations should have enough inventory capacity to fulfill or recieve one train-load)
- Have one station be an unload station(requester) that has the "trains keep full if under X" slider set to max.
- Have two stations that provide the good/are set to load the good.
- Have one of the provider stations set to a higher priority than the other
- Observe that the train schedules a delivery randomly from one of the two providers without a discernible pattern and without taking the priority settings into account (you can repeatedly "recover the train" with unity to see the route without having to wait for actual loading/unloading)
Game version and build number
v0.8.3a b578
Operating system
Windows
Attachments
Test Priority Trainstations.save