Fixed 0 appearing sometimes in the CustomModelData

Author: ImCodist

src/main/java/xyz/imcodist/ui/ActionEditorUI.java

@@ -221,6 +221,7 @@ private Integer getCustomModelData(ItemStack item) {
                 NbtElement nbtElement = item.getNbt().get("CustomModelData");
                 if (nbtElement != null) {
                     existingCustomModelData = Integer.parseInt(nbtElement.toString());
+                    if (existingCustomModelData == 0) existingCustomModelData = null;
                 }
             }