Describe the bug
it is a bug that occurs in tenders that dont have any coal slots, it makes the GUI almost impossible to use

How to reproduce
Steps to reproduce the unwanted behavior:

1. make a tender
2. set the amount of coal you can carry to 0

Expected behavior
same kind of GUI as Tankers

Screenshots
https://cdn.discordapp.com/attachments/713420281833848845/775053860917346304/2020-11-08_18.04.17.png

System Information
OS: Windows

System Memory: "16gb"

Allocated Memory: "8gb"

CPU: "AMD Ryzen 3 1200"

GPU: "Gigabyte GTX1050"

IR-Version: "1.8 1.12.2 test version"

Forge-Version: "1.12.2 - 14.23.5.2845"

Modlist
https://media.discordapp.net/attachments/713420281833848845/775053225271361556/unknown.png?width=754&height=671

latest.log
https://pastebin.com/nx39yrDT

Additional context
maybe make it so it displays it the same way as a tanker?