MINOR: ssl: convert to binary ssl_fc_unique_id and ssl_bc_unique_id.

MINOR: ssl: convert to binary ssl_fc_unique_id and ssl_bc_unique_id.

Previously ssl_fc_unique_id and ssl_bc_unique_id return a string encoded
in base64 of the RFC 5929 TLS unique identifier. This patch modify those fetches
to return directly the ID in the original binary format. The user can make the
choice to encode in base64 using the converter.

i.e. : ssl_fc_unique_id,base64