BUG/MINOR: ssl: ssl_sock_parse_clienthello ignores session id

BUG/MINOR: ssl: ssl_sock_parse_clienthello ignores session id

In ssl_sock_parse_clienthello(), the code considers that SSL Sessionid
size is '1', and then considers that the SSL cipher suite is availble
right after the session id size information.
This actually works in a single case, when the client does not send a
session id.

This patch fixes this issue by introducing the a propoer way to parse
the session id and move forward the cursor by the session id length when
required.

Need to be backported to 1.8.