Newly added markers do not persist to markers.yml after reload

[RoyCurtis]

Tested on

• Cauldron-MCPC-Plus version git-Cauldron-MCPC-Plus-1.7.10-1.1207.01.198 (MC: 1.7.10) (Implementing API version 1.7.10-R0.1-SNAPSHOT)
• Using either Dynmap v2.0.0-alpha-3 for MC 1.7.10 (Forge 10.13.0+) or Dynmap v2.0.0 for MC 1.7.10 (Forge 10.13.0)
• With either DynmapCBBridge-2.0.0-alpha-2.jar or DynmapCBBridge for v2.0.0
• Using icon markers and line markers on various sets
• Plugins used, mods used
• Log: https://gist.github.com/RoyCurtis/ae4e0937cd666d8424a8

Reproduction

1. Start a 1.7.10 Cauldron/Forge server with DynmapForge
2. Do command /dmarker add icon:tree test1
3. Open markers.yml in the dynmap directory of the server. Observe that it has an entry for test1.
4. Do command /dynmap reload
5. Do command /dmarker add icon:tree test2
6. Repeat step 3. Observe that no entry for test2 is found.

Workaround

Only workaround found so far is to restart the entire server