Fix tier in chemplant error display (#856)

fix tier

src/main/java/gtPlusPlus/xmod/gregtech/common/tileentities/machines/multi/production/chemplant/GregtechMTE_ChemicalPlant.java

@@ -563,7 +563,7 @@ protected ProcessingLogic createProcessingLogic() {
  @Override
  protected CheckRecipeResult validateRecipe(@NotNull GT_Recipe recipe) {
  if (recipe.mSpecialValue > mSolidCasingTier) {
- return CheckRecipeResultRegistry.insufficientMachineTier(recipe.mSpecialValue);
+ return CheckRecipeResultRegistry.insufficientMachineTier(recipe.mSpecialValue + 1);
  }
  // checks if it has a catalyst
  ItemStack catalystInRecipe = null;