Javalin only binds to localhost

Summary: Javalin only binds to localhost

Affected component(s): Mod

Affected version(s): All

Steps to reproduce:

1. Change web server's target server IP
2. Run Minecarft server

Expected behaviour: Web server connects to Beacon successfully

Detailed description: By default, Javalin binds to "localhost". We should be able to specify its binding address, defaulting to "0.0.0.0"