[Bug] DXL Importer fails when using a custom world container

Greetings, I found out that attempting to import DXL worlds with /dxlimport fails if you have a custom world container set in your startup flags. It fails stating that the map you are trying to import does not exist. (Setting a custom world container will store your worlds in a folder instead of in the root directory of the server for better organization.)

Steps to reproduce:

1. Add --world-container worlds to your server startup flags, OR add the line world-container: worlds to bukkit.yml
2. Start your server and attempt to /dxlimport a DXL map.

Server Information:

• Paper 1.19 (Build 66)
• MythicDungeons 1.0.3 (Build 24)