Fix issue #1522

`TakeLast` should ignore other `request`s if it's requested with `Long.MAX_VALUE`. #1522
Here I try to ignore the further requests after `request(Long.MAX_VALUE)`. I cannot use `getAndAdd` because if `requested == Long.MAX_VALUE`, I wanna ignore `n`. If adding `n` to `requested`, and if it happens to execute in `while (true)` loop in `emit` method, the loop won't stop.