Replaced an explicit loop with a a replace().

I am not sure we need an IIFE around it. Just to hide `r`? I don't have enough knowledge of internals to make a call.

Another thing is a slight functional difference between the old code and the new one. The old one, when faced with a string like that: `"a=1=2", will create an entry with key `"a"`, and value `"1"`, while the new one will create an entry with key `"a"`, and value `"1=2"`. Granted the whole case is a pathological one, and I hope it never happens, yet there is a difference. I think that the new way to handle it is more correct than the old one.