BUG/MEDIUM: ssl-gencert: Don't forget to free memory when done

BUG/MEDIUM: ssl-gencert: Don't forget to free memory when done

In ssl_sock_do_create_cert(), don't forget to free ctmp and tmp_ssl once
we're done creating the certificate, otherwise we will get a memory leak
each time we have to create a new certificate, which will happen each
time a new SNI is used.

This should be backported as far as 2.6 (though on older releases,
ssl_gencert.c doesn't exist, and that function is found in ssl_sock.c).

This patch was submitted by Red Hat and AISLE Research