ssl: OpenSSL 0.9.8 can support ECDH as well

It's true that ECDH ciphers are not in the default cipher suites in this
release, but it fully supports ECDH and if you explicitely ask for theses
cipher, it will work just fine.

Signed-off-by: Sylvain Munaut <tnt@246tNt.com>
Merge pull request #1028 from smunaut/fix_ecdh_openssl_0.9.8

ssl: OpenSSL 0.9.8 can support ECDH as well