I know my setup is a bit crazy, but whatever....
I set up Nginx on Openshift to cache map tiles (for a map viewer, you can guess the purpose, :-) ) that are served from my home network, which has limited bandwidth (stupid wireless connections!). Openshift gives me unlimited bandwidth and 1 GB of disk, which should be enough to cache popular portions of the map.
However, the map viewer likes to make requests like this:
Which makes nginx think the file is not cacheable! I've done some googling, but since I'm horrible at reading and writing regexes, I would like to request (from you) a way to make nginx ignore the query string for .png files and just serve the version from cache without the query string.
Here are the relevant parts of the server config: