Current (gradual) calculations occasionally panic

[Chiffario]

Steps to replicate:

• Run osu! and rosu-memory
• Watch a replay (seems to be non-specific)

Expectation: rosu-memory runs just fine

Result: rosu-memory panics with an error on L596

Seems to be a regression from my initial fix of potential extra triggers of gradual.nth(). Requires investigating

I wasn't able to replicate this behaviour on linux so far, might be related to a different issue

[486c]

Workaround implemented in #49 Still requires heavy debugging to found root cause. not gonna close

[486c]

FYI: You can almost always replicate this behaviour when starting rosu-memory mid map