Prevent NPE from querying toolbelt before capability initialization (#2721)

Author: M-W-K

src/main/java/gregtech/api/items/toolitem/ItemGTToolbelt.java

@@ -43,6 +43,7 @@
 import net.minecraftforge.fml.relauncher.Side;
 import net.minecraftforge.fml.relauncher.SideOnly;
 import net.minecraftforge.items.CapabilityItemHandler;
+import net.minecraftforge.items.IItemHandler;
 import net.minecraftforge.items.ItemStackHandler;
 import net.minecraftforge.oredict.OreDictionary;
 import net.minecraftforge.oredict.OreIngredient;
@@ -410,7 +411,9 @@ public boolean supportsTool(ItemStack stack, ItemStack tool) {
     }
 
     private ToolStackHandler getHandler(ItemStack stack) {
-        return (ToolStackHandler) stack.getCapability(CapabilityItemHandler.ITEM_HANDLER_CAPABILITY, null);
+        IItemHandler handler = stack.getCapability(CapabilityItemHandler.ITEM_HANDLER_CAPABILITY, null);
+        if (handler instanceof ToolStackHandler h) return h;
+        else return FALLBACK;
     }
 
     @Override
@@ -601,6 +604,8 @@ public void readNBTShareTag(ItemStack stack, NBTTagCompound nbt) {
         stack.setTagCompound(nbt == null ? null : (nbt.hasKey("NBT") ? nbt.getCompoundTag("NBT") : null));
     }
 
+    protected static final ToolStackHandler FALLBACK = new ToolStackHandler(0);
+
     protected static class ToolStackHandler extends ItemStackHandler {
 
         private static final Set<String> EMPTY = ImmutableSet.of();