OpenSSL engines directory path

[Eugene Grosbein]

Hi!

FreeBSD 12+ has OpenSSL version that supports loading additional "engines" (shared libraries).
Default path for engines in FreeBSD is /usr/lib/engines currently.
The path for security/openssl111 port (needed for FreeBSD 11) is ${LOCALBASE}/lib/engines-1.1

Please consider updating ports/Mk/Uses/ssl.conf with something like OPENSSLENGINES
that should equal to ${OPENSSLLIB}/engines when SSL_DEFAULT is "base"
and for openssl111 it should be ${OPENSSLLIB}/engines-1.1

This would help porting engines.