Release/19.1.1+laterpay2

@doismellburning Here is the change we're deploying, probably not really worth merging into laterpay/gunicorn@master. I prepared the PR sans version change in [feature/921-ignore-async-handle_request-socket-error|https://github.com/laterpay/gunicorn/compare/feature/921-ignore-async-handle_request-socket-error?expand=1] to benoitc/gunicorn.

Once you approve this, I'll file PRs against everything that uses gunicorn for testing and push -laterpay2 to pypi.laterpay.net.