This is a fix related to how NinjaCentral names their NZB files.
All their NZBs have a dash + four characters appended to the filename/name of the NZB.
A few examples: `-ASn1` `-xm98` `-s4n4` - and so on
This reg-ex/reg-ex-replace works by removing that part only. I've had this reg-ex in my clean.py script for quite a long time, and haven't observed any negative effects with using this, with a lot of different NZB indexers simultaneously.
A reg-ex test:
https://regex101.com/r/KD8uqu/1