Issue Description: In recent versions of Dynmap, message list in the web viewer does not render properly.

• This problem has existed since at least 1.20 or earlier.
• Message list is rendered below the chat input box, obscuring the input box when a message shows up. (First image)
• It used to look like (and should look like) the second image, where the message list completely covers the input box. I could reproduce it by giving padding-bottom: 32px to the div.messagelist element.
• I tried to modify the css for a permanent fix, but whenever the plugin is restarted, it completely discards my change and rolls back to the factory default.

• Dynmap Version: Dynmap 3.7 Snapshot
• Server Version: Paper 1.21.5
• Pastebin of Configuration.txt: https://pastebin.com/eqPeVh6J
• Server Host (if applicable): Self hosted