curl: CVE-2026-111954: upload reader failed redirect UAF

Summary: Curlreqhardreset lib/request.c line 124 in curl-8230 calls Curlclientreset while req-rewindread may still be set, which keeps the client reader stack for a rewind lib/sendf.c line 82, and only clears the flag at line 157, so the kept stack is never rewound or freed and is still installed...