Fix for shulker dispenser behaviour

Fixes the behaviour of dispensers to remove 2 shulker boxes from a stack instead of 1

src/main/java/carpet/mixins/BlockPlacementDispenserBehaviourMixin.java

@@ -0,0 +1,21 @@
+package carpet.mixins;
+
+import carpet.CarpetSettings;
+import net.minecraft.block.dispenser.BlockPlacementDispenserBehavior;
+import net.minecraft.item.ItemStack;
+import org.spongepowered.asm.mixin.Mixin;
+import org.spongepowered.asm.mixin.injection.At;
+import org.spongepowered.asm.mixin.injection.Redirect;
+
+@Mixin(BlockPlacementDispenserBehavior.class)
+public class BlockPlacementDispenserBehaviourMixin
+{
+    @Redirect(method = "dispenseSilently", at = @At(value="INVOKE", target="Lnet/minecraft/item/ItemStack;decrement(I)V"))
+    private void cancleDoubleDecrement(ItemStack stack, int amount)
+    {
+        if (!CarpetSettings.b_stackableShulkerBoxes)
+        {
+            stack.decrement(amount);
+        }
+    }
+}