By looking at the code !quality, I wouldn't be surprised to learn that they have no tests at all.
Granted. This should move outside of the web root, but just looking at this one file that just sets up configuration values provides no ground to say anything about general code quality
No it doesn't. Having to modify live code just to change configuration options is bad. If I want to add a new slave, or change some configuration option, it should have no affect on running code. I shouldn't be changing any software logic, and that's exactly what editing this file does.
Their are standard ways to avoid this. But no, if changing your config file means changing what essentially amounts to changing the executable of your code, you're asking for trouble.