build: enable SASL_{SCRAM,OAUTHBEARER} when SSL is enabled
build: enable SASL_{SCRAM,OAUTHBEARER} when SSL is enabled

This makes the CMake build system match the default build system, which
unconditionally enables the SCRAM/OAUTHBEARER SASL methods when SSL is
enabled.

fede1024/rust-rdkafka,fede1024/rust-rdkafka,fede1024/rust-rdkafka