Fixed deserialization of "CustomBlock" in graveyards
This should fix problems with AngelChests in Graveyards either not generating, or not properly getting removed after the plugin was reloaded or the server restarted. Sorry for the trouble!
If you still use the same graveyards.yml config as you did before updating to 7.0.0 or later, please be sure that the "material" options in your graveyards.yml are valid according to the explanation about the "material" option in config.yml