I dug a bit on whether HTTP 1.0 is even still in use, found this from 2k9 on an [erlang mailing list](https://groups.google.com/forum/#!msg/erlang-programming/9jG_SHjvs84/dO9WUS239ggJ):

> Talking to the NginX developers, I have clarified a couple of things:
>
> 1) HTTP/1.0 is in use by proxies, some mobile clients, and IE when configured to use a proxy. So 1.0 appears to still account for a non-trivial % of traffic on the web overall.

I don't know which IE version.