httpc: fix reading data in a chunked request

There was a problem: chunked request to etcd via TLS using builtin http
client returns nothing. The problem was reproduced quite often by a test
`integration.general.tls` in etcd-client Lua module. The patch updates
curl submodule to a version based on 8.5.0 release with applied patch
with fix [1].

The patch also removes workaround for aforementioned problem made in
commit aa58c212 ("httpc: use http 1.1 by default").

1. https://github.com/curl/curl/commit/cdd905a9854305657ebbe645095e1189dcda28c7

Fixes #9547

NO_TEST=etcd-client tests
NO_DOC=bugfix