Issue title: LinkageError "Make sure you're not using this jar for multiple server instances!"
 Issue body: [ProtocolLib] Encountered a LinkageError. Make sure you're not using this jar for multiple server instances!
- Server is using latest dev build of ProtocolLib (4.2.1)
- Minigame server will sometimes be unjoin-able for [Proxy] Lost connection to server
Error Log:
https://puu.sh/vqPtT/7be38a0dda.txt

Protocol Dump:
https://puu.sh/vqQ46/0c435fe81e.txt
 Comments: 
 Comment 0: I suppose the first question is are you using it for multiple server instances?
 Comment 1: No, each server uses its own protocolLib jar
 Comment 2: Hmm well this is new. Unfortunately, linkage errors are notoriously difficult to pin down. My first guess is that it has to do with "MineHeroesSpigot". Could you try using regular Spigot and see if the problem persists?
 Comment 3: Any more info on this?
 Comment 4: got the same issue, it happen only with my factions server in rare case (i am using 1.8.8 + viaversion) using 4.2.0
https://hastebin.com/zowusigobu.md
 Comment 5: Hello,
i have the same problem
 Comment 6: Same issue with us.
 Comment 7: This issue is still not fixed. 
 Comment 8: Issue is not fixed, happen more often with factions server and rarely in other server
{'source': 'GithubIssues', 'repo_name_with_owner': 'dmulloy2/ProtocolLib', 'issue_id': 223218963, 'repo_stars': 626.0}