Issue Description: Cannot write errors when connecting to external webserver

• Dynmap Version: v3.1 for Forge 1.12.2
• Server Version: forge 1.12.2
• Pastebin of Configuration.txt: https://paste.gg/p/anonymous/466519d414624cb6ab07be85fb1055e6
• Server Host (if applicable): ApexMC, External is Ubuntu 20
• Pastebin of crashlogs or other relevant logs: https://paste.gg/p/anonymous/43cf0a1da7234201a3c668223643950b
• Steps to Replicate: Setup an external webserver according to the guide, and restart the server

I don't know why it's not properly loading, I've set up apache and I can visit the link without issues, although nothing shows up & it does not send the tiles to external webserver.
Did I set something up wrong, or is this a bug?