Issue description:

Whitelist Latex in a disk manipulator to import from a fluid disk into a system lead to a crash. I can't open the save anymore, it now always crashes with the same error (see below)

What happens:

Time: 08/12/19 09:12
Description: Exception in server tick loop

Version (make sure you are on the latest version before reporting):

• Minecraft: 1.14.4
• Forge: 28.1.96
• Refined Storage: 1.7.1

If a (crash)log is relevant for this issue, link it here:

java.lang.IllegalStateException: Can't modify the empty stack.
at net.minecraftforge.fluids.FluidStack.setAmount(FluidStack.java:174) ~[?:?] {re:classloading}
at com.raoulvdberge.refinedstorage.util.StackUtils.copy(StackUtils.java:275) ~[?:1.7.1] {re:classloading}
at com.raoulvdberge.refinedstorage.apiimpl.network.node.diskmanipulator.StorageDiskFluidManipulatorWrapper.insert(StorageDiskFluidManipulatorWrapper.java:72) ~[?:1.7.1] {re:classloading}
at com.raoulvdberge.refinedstorage.apiimpl.network.node.diskmanipulator.StorageDiskFluidManipulatorWrapper.insert(StorageDiskFluidManipulatorWrapper.java:20) ~[?:1.7.1] {re:classloading}
at com.raoulvdberge.refinedstorage.apiimpl.network.node.diskmanipulator.DiskManipulatorNetworkNode.insertFluidIntoNetwork(DiskManipulatorNetworkNode.java:288) ~[?:1.7.1] {re:classloading}
at com.raoulvdberge.refinedstorage.apiimpl.network.node.diskmanipulator.DiskManipulatorNetworkNode.update(DiskManipulatorNetworkNode.java:168) ~[?:1.7.1] {re:classloading}
at com.raoulvdberge.refinedstorage.apiimpl.network.NetworkNodeListener.onWorldTick(NetworkNodeListener.java:26) ~[?:1.7.1] {re:classloading}
at net.minecraftforge.eventbus.ASMEventHandler_717_NetworkNodeListener_onWorldTick_WorldTickEvent.invoke(.dynamic) ~[?:?] {}
at net.minecraftforge.eventbus.ASMEventHandler.invoke(ASMEventHandler.java:80) ~[eventbus-1.0.0-service.jar:?] {}
at net.minecraftforge.eventbus.EventBus.post(EventBus.java:258) ~[eventbus-1.0.0-service.jar:?] {}
at net.minecraftforge.fml.hooks.BasicEventHooks.onPostWorldTick(BasicEventHooks.java:99) ~[?:?] {re:classloading}
at net.minecraft.server.MinecraftServer.func_71190_q(MinecraftServer.java:835) ~[?:?] {re:classloading,pl:accesstransformer:B}
at net.minecraft.server.MinecraftServer.func_71217_p(MinecraftServer.java:764) ~[?:?] {re:classloading,pl:accesstransformer:B}
at net.minecraft.server.integrated.IntegratedServer.func_71217_p(IntegratedServer.java:112) ~[?:?] {re:classloading,pl:runtimedistcleaner:A}
at net.minecraft.server.MinecraftServer.run(MinecraftServer.java:622) [?:?] {re:classloading,pl:accesstransformer:B}
at java.lang.Thread.run(Thread.java:748) [?:1.8.0_232] {}