Issue Description: In Forge, placing a (vanilla) sign with the correct [dynmap] formatting doesn't create a marker, and just stays as plain text. Sign markers are enabled in the config and players have permission to create them.

• Dynmap Version: Dynmap-3.6-forge-1.20
• Server Version: Forge 1.20.1 47.1.3
• Pastebin of Configuration.txt: https://pastebin.com/5SETL3z2
• Server Host (if applicable): MCProHosting
• Pastebin of crashlogs or other relevant logs: No crash logs
• Other Relevant Data/Screenshots: Other mods: DynmapBlockScan 3.6-forge-1.20, Patchouli 1.20.1-81-FORGE, TerraFirmaCraft Forge-1.20.1-3.1.4-beta, Just Enough Items 1.20.1-forge-15.3.0.1.
• Steps to Replicate: Install Dynmap on a Forge 1.20 server. Make sure sign markers are enabled in the config and players have permission. Place a vanilla oak sign and type in the [dynmap] formatting for a sign marker - and note that it doesn't create a marker, but stays as plain text.

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

it only works on vanilla signs, not modded versions

@JurgenKuyper Thanks, is there any way mods can make their signs compatible with dynmap?

you can hook into the marker api and do the sign creation yourself using a custom plugin yeah

I've just realised that this issue actually isn't specific to TFC - sign markers don't work in Forge at all, even vanilla signs. I'm guessing it's something to do with this commented out block?