fixes #44.

The problem was that version 0.4.35 of chronotope/chrono removes all methods that allow to import a timestamp from another timezone than UTC (https://github.com/chronotope/chrono/releases/tag/v0.4.35):

We deprecated all timestamp-related methods on NaiveDateTime. The reason is that a timestamp is defined to be in UTC. The NaiveDateTime type doesn't know the offset from UTC, so it was technically wrong to have these methods. The alternative is to use the similar methods on the DateTime<Utc> type, or from the TimeZone trait.

So, this functionality has also been removed from dfir-toolkit and -- especially -- from mactime2.