BUILD: ssl: fix to build (again) with boringssl

Limitations:
. disable force-ssl/tls (need more work)
should be set earlier with SSL_CTX_new (SSL_CTX_set_ssl_version is removed)
. disable generate-certificates (need more work)
introduce SSL_NO_GENERATE_CERTIFICATES to disable generate-certificates.

Cleanup some #ifdef and type related to boringssl env.
2 files changed