tproxy/worker: stop using gevent 0.13 workaround

This could probably be fixed more cleanly than simply commenting out
those two lines, but since we know that we'll always be using a modern
gevent, simple commenting out works fine.
tproxy/worker.py: backwards-compatible fix for gevent workaround

May as well fix this the proper way.
Merge pull request #1 from angaza/dev-modern-gevent-angaza

tproxy/worker: stop using gevent 0.13 workaround