Overpass API developpement

[mmd <>]

> 
> Not sure how to move on from here. Might be some CGI issue in Apache in
> conjunction with the HTTP/1.1 keep alive option, maybe?
> 

adding to that, the error is reproducible even with a trivial hello
world c++ binary called via CGI in the load test scenario mentioned
earlier on.

I could also trigger it by running several curl processes in parallel
and http keep alive mode.

Looks like some Apache issue to me.