Merge branch 'll/curl-accept-language'

Earlier, HTTP transport clients learned to tell the server side
what locale they are in by sending Accept-Language HTTP header, but
this was done only for some requests but not others.

* ll/curl-accept-language:
  remote-curl: send Accept-Language header to server

diff --cc http.c
Simple merge

diff --cc t/t5550-http-fetch-dumb.sh
Simple merge