Fix rendering fluids inside machine previews

Fixes #378

Author: davenonymous

src/main/java/org/dave/compactmachines3/world/WorldProviderMachines.java

@@ -1,7 +1,10 @@
 package org.dave.compactmachines3.world;
 
+import net.minecraft.init.Biomes;
+import net.minecraft.util.math.BlockPos;
 import net.minecraft.world.DimensionType;
 import net.minecraft.world.WorldProvider;
+import net.minecraft.world.biome.Biome;
 import net.minecraft.world.border.WorldBorder;
 import net.minecraft.world.gen.IChunkGenerator;
 import org.dave.compactmachines3.misc.ConfigurationHandler;
@@ -45,4 +48,13 @@ public WorldBorder createWorldBorder() {
     public boolean doesWaterVaporize() {
         return ConfigurationHandler.CompatSettings.doesWaterVaporize;
     }
+
+    @Override
+    public Biome getBiomeForCoords(BlockPos pos) {
+        if(world == null) {
+            return Biomes.PLAINS;
+        }
+
+        return super.getBiomeForCoords(pos);
+    }
 }