[boost-safe-numerics] build error on x64-windows

Copy issue body from D:/Git/vcpkg/insPackage: boost-safe-numerics:x64-windows@1.91.0

**Host Environment**

- Host: x64-windows
- Compiler: MSVC 19.44.35228.0
- CMake Version: 4.3.3
- vcpkg-tool version: 2026-05-27-d5b6777d666efc1a7f491babfcdab37794c1ae3e
vcpkg-scripts version: 7012bf7bc3 2026-07-14 (5 hours ago)

**To Reproduce**

`vcpkg install boost`

**Failure logs**

```
Downloading https://github.com/boostorg/safe_numerics/archive/boost-1.91.0.tar.gz -> boostorg-safe_numerics-boost-1.91.0.tar.gz
error: curl operation failed with error code 35 (SSL connect error).
error: Not a transient network error, won't retry download from https://github.com/boostorg/safe_numerics/archive/boost-1.91.0.tar.gz
note: If you are using a proxy, please ensure your proxy settings are correct.
Possible causes are:
1. You are actually using an HTTP proxy, but setting HTTPS_PROXY variable to `https://address:port`.
This is not correct, because `https://` prefix claims the proxy is an HTTPS proxy, while your proxy (v2ray, shadowsocksr, etc...) is an HTTP proxy.
Try setting `http://address:port` to both HTTP_PROXY and HTTPS_PROXY instead.
2. If you are using Windows, vcpkg will automatically use your Windows IE Proxy Settings set by your proxy software. See: https://github.com/microsoft/vcpkg-tool/pull/77
The value set by your proxy might be wrong, or have same `https://` prefix issue.
3. Your proxy's remote server is out of service.
If you believe this is not a temporary download server failure and vcpkg needs to be changed to download this file from a different location, please submit an issue to https://github.com/Microsoft/vcpkg/issues
CMake Error at scripts/cmake/vcpkg_download_distfile.cmake:136 (message):
Download failed, halting portfile.
Call Stack (most recent call first):
scripts/cmake/vcpkg_from_github.cmake:120 (vcpkg_download_distfile)
ports/boost-safe-numerics/portfile.cmake:3 (vcpkg_from_github)
scripts/ports.cmake:206 (include)

```

talled/vcpkg/issue_body.md

Start by reproducing `vcpkg install boost` on the reported x64-windows environment and inspect the failure at scripts/cmake/vcpkg_download_distfile.cmake:136, called through vcpkg_from_github.cmake and ports/boost-safe-numerics/portfile.cmake. Determine whether the SSL error is reproducible in vcpkg or specific to the proxy/network setup; done means a project-side failure and actionable scope are established.

Written by the indexing model from the issue text.