:warning: method redefined; discarding old response_http_version
:warning: method redefined; discarding old response_http_version

This method is defined twice, with slightly different implementation.
The first one takes `response.env`, and the second one takes `response.header`.
I'll leave the second one which is alive in the released versions of gems.

r7kamura/autodoc,r7kamura/autodoc,r7kamura/autodoc