Sometimes it may be considered a security risk to load an external
OpenSSL configuration automatically inside curl_global_init(). The
configuration option --disable-ssl-auto-load-config disables this
automatism. The Windows build scripts winbuild/Makefile.vs provide a
corresponding option ENABLE_SSL_AUTO_LOAD_CONFIG accepting a boolean
value.
Setting neither of these options corresponds to the previous behavior
loading the external OpenSSL configuration automatically.
Fixes#2724Closes#2791