After the wheel-spinning of the past few episodes, it’s increasingly clear that “Serial” is probably not going to end with Sarah Koenig solving the murder of Hae Min Lee. And that’s okay! In real life, Koenig would probably tell you that’s not the point. In this Funny or Die parody, though, she has a somewhat different reaction. You’ve only got 24 hours left to laugh at MailKimp jokes, everybody.