I change the format of the config file to a new better way.

I also added a few more options:

Allow Milk:
If set to false, viruses will persist and won't be remove.

Allow Flying:
If set to true, players that are flying with elytra will still have a chance to get the virus. If false, player won't be able to get them while flying.

Since most of the information are on Config file, I added a reload command, bvreload, to easily reload the config file.

Bug Fix:
/reload and /bvreload
- Will now remove all the viruses for all online players but not any other effect.
- Fixed, If the player died, they will no longer get the Virus.
- Fixed, when the server reload, offline player will still have the virus
- and some other minor bugs
- I made sure to not touch any other effects when removing the viruses when using command or server reload/restart, or any event in minecraft. So it won't remove some very good effect like "Hero of the Village".

If you still encounter bugs, please post it below. it will help me greatly!