Fixed uwsgi

There are some weird quirks to using pypy, seems like having the compiler
around in production is mandatory.

Also, uwsgi's development cycle is permanently fucked. They've been
working on 2.1 for a decade. 2.0 is still the stable, and what's pushed
to PyPI, but there are definitely some 2.1 bits that have slipped
through. Case in point, the pypy plugin depends on 2.1 C APIs.
Anyway, I'm living at HEAD now.

Experimental pypy2+uwsgi container