http: accept https:// proxies again
Since 663d7abe07ea (http: reject unsupported proxy URL schemes, 2026-05-05), set_curl_proxy_type() returns 0 only for the "http" and SOCKS variants via dedicated early returns, and -1 for everything else. The "https" branch configures the CURL handle for HTTPS proxying but then falls through to the trailing `return -1` intended for unknown schemes, so the caller in get_curl_handle() treats a perfectly valid https:// proxy URL as unsupported and refuses to use it. Noticed while looking into a Coverity report against the same function; the unchecked curl_easy_setopt() return values it flags are orthogonal to this fix. Assisted-by: Opus 4.7 Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de> Signed-off-by: Junio C Hamano <gitster@pobox.com>