Change Details

Avoid calling a few ENGINE_* functions LibreSSL does not provide.

LibreSSL doesn't support the ENGINE API and defines the OPENSSL_NO_ENGINE feature flag, tor uses that feature flag, but misses to include `openssl/opensslconf.h` which is necessary to pull in the feature flags at least with LibreSSL, therefore add that include.

Avoid calling a few ENGINE_* functions LibreSSL does not proviLibreSSL doesn't support the ENGINE API and defines the OPENSSL_NO_ENGINE feature flag, tor uses that feature flag, but misses to include `openssl/opensslconf.h` which is necessary to pull in the feature flags at least with LibreSSL, therefore add that include.