Fix another NPE with Mystcraft lightning. Related #392.
Update Spigot patch: 0024 Metrics. Rewrite the Metrics system to be closer to the Bukkit version.

https://github.com/EcoCityCraft/Spigot/blob/7db53a4407d49fd69c30ee29ad68499a6fac51b0/CraftBukkit-Patches/0024-Metrics.-Rewrite-the-Metrics-system-to-be-closer-to-.patch