Compilation warning on Windows

[Tectu]

Scenario:

• Windows 10 64-bit
• GCC 10.3.0 (from MSYS2)
• boost 1.75.0

Compiling an application using certify in the scenario listed above yields the following compilation warnings:

In file included from C:/Users/joel/Documents/projects/malloy/lib/malloy/client/3rdparty/boost/certify/https_verification.hpp:33,
                 from C:\Users\joel\Documents\projects\malloy\lib\malloy\client\controller.cpp:7:
C:/Users/joel/Documents/projects/malloy/lib/malloy/client/3rdparty/boost/certify/detail/keystore_windows.ipp: In function 'std::unique_ptr<const _CERT_CONTEXT, boost::certify::detail::cert_context_deleter> boost::certify::detail::create_cert_ctx(stack_st_X509*)':
C:/Users/joel/Documents/projects/malloy/lib/malloy/client/3rdparty/boost/certify/detail/keystore_windows.ipp:85:21: warning: passing NULL to non-pointer argument 3 of 'void* CertOpenStore(LPCSTR, DWORD, HCRYPTPROV_LEGACY, DWORD, const void*)' [-Wconversion-null]
   85 |                     NULL,
      |                     ^~~~
In file included from C:/Users/joel/Documents/projects/malloy/lib/malloy/client/3rdparty/boost/certify/detail/keystore_windows.ipp:8,
                 from C:/Users/joel/Documents/projects/malloy/lib/malloy/client/3rdparty/boost/certify/https_verification.hpp:33,
                 from C:\Users\joel\Documents\projects\malloy\lib\malloy\client\controller.cpp:7:
C:/msys64/mingw64/x86_64-w64-mingw32/include/wincrypt.h:3966:108: note:   declared here
 3966 | WINIMPM HCERTSTORE WINAPI CertOpenStore (LPCSTR lpszStoreProvider, DWORD dwEncodingType, HCRYPTPROV_LEGACY hCryptProv, DWORD dwFlags, const void *pvPara);
      |                                                                                          ~~~~~~~~~~~~~~~~~~^~~~~~~~~~