Issue Description: When using a bucket with periods in the name there's an error preventing the connection. This issue prevents setting up a CNAME for use with a subdomain

NOTE: In the files below map.domain.com is used as an example

• Dynmap Version: v3.4-beta-5-806
• Server Version: git-Purpur-1692
• Pastebin of Configuration.txt: https://pastebin.com/7d6pqcAU
• Server Host (if applicable): Self-hosted
• Pastebin of crashlogs or other relevant logs: https://pastebin.com/JeLXWEji
• Steps to Replicate: Use any bucket with periods in the name

[✓] I have looked at all other issues and this is not a duplicate
[✓] I have been able to replicate this

The bucket name is the AWS identifier, not the DNS name - you can add a CNAME if you want, but you cannot use that for the bucket name: the APIs to AWS are HTTPS, and a CNAME will not have the needed SSL certificate on the AWS APIs for the bucket, the calls to deliver data to the bucket will be unusuable.