Use the first cipher suite sent by the client

If encrypted, use the TLS_RSA_WITH_AES_128_CBC_SHA; otherwise, use the
first cipher suite sent by the client. This complements the last commit
and makes this module work with SSLv3, TLSv1.0, TLSv1.1, and TLSv1.2
when NEGOTIATE_TLS is not enabled (see
https://gist.github.com/rcvalle/10335282).