Register mine class onDisable

[CullanP]

Fix class not found errors for 1.8.3, No issues should occur on 1.7 (Untested though)

[jjkoletar]

May I ask what causes the current implementation (https://github.com/jjkoletar/MineResetLite/blob/master/src/com/koletar/jj/mineresetlite/MineResetLite.java#L60-L62) to now work? In theory, Spigot is loading the main plugin class before loading any serialized data, so it should work

[Byteflux]

This is still an issue in 1.8.7