clojure.core/proxy does not work when one reloads namespace containing defprotocol.

E.g. one can't reload the following file without triggering an error:

Saving the above as foo/baz.clj, I get the following error:

I'm using the current git master (commit 5cfe5111ccb5afec4f9c73), but clojure 1.7 has the same problem.

The problem is that proxy-name only uses the interface names as a key. These names do not change when reloading the namespace, but the interfaces themself are new.

I'm going to attach a short patch which fixes that issue for me.