Always set (EC)DH parameters

Don't skip setting (EC)DH parameters when the first connection after
starting the server happens to be outgoing, because the OpenSSL context
will later be reused when accepting incoming connections.  This makes
sure that ephemeral (EC)DH cipher suites can be offered either way.
Merge pull request #9 from weiss/always-set-dh-params

Always set (EC)DH parameters