General Changes:
- Fixed not being able to summon Rune Guardians.
- Changed some default config values around.

Side notes: I would change these values in your default config.yml if you are running a normal survival server or a survival server with armor above vanilla enchants or custom enchantments.

Rune Guardian Damage: 3 -> 8
Rune Guardian Health: 100 -> 150
Rune Drop Chance: 50 -> 35
Rune Guardian MovementSpeed: 0.25 -> 0.3

These just make them a bit harder to kill since they are very easy to kill at the moment. These are just based on some testing so take them as a rough result and modify them at your own wish.

Again, if there are any bugs or errors, please let me know so I can fix them ASAP.

Thanks to @bumbble for reporting the not being able to summon Rune Guardians.