fix(rustup-init/sh): fix incorrect TLS warning with curl v8.10

[rami3l]

Closes #4045, as discussed in #4045 (comment).

Tested locally on Alpine Linux v3.20 aarch64 with the following cURL distribution:

> curl --version
curl 8.10.1 (aarch64-alpine-linux-musl) libcurl/8.10.1 OpenSSL/3.3.2 zlib/1.3.1 brotli/1.1.0 zstd/1.5.6 c-ares/1.33.1 libidn2/2.3.7 libpsl/0.21.5 nghttp2/1.62.1
Release-Date: 2024-09-18
Protocols: dict file ftp ftps gopher gophers http https imap imaps ipfs ipns mqtt pop3 pop3s rtsp smb smbs smtp smtps telnet tftp ws wss
Features: alt-svc AsynchDNS brotli HSTS HTTP2 HTTPS-proxy IDN IPv6 Largefile libz NTLM PSL SSL threadsafe TLS-SRP UnixSockets zstd

[djc]

Nice!