fix tls config, accept any server name

One change I have noticed is this.

This is something I will not merge as it renders the TLS connection insecure for everyone. It would absolutely have to be a configuration options. However, I'm not sure why this is required since in all use cases I know of the server certificate is always known.

I am aware of a breaking change when building with Go 1.3 though, referred to here:
https://github.com/elasticsearch/logstash-forwarder/pull/205

Is this what you are attempting to resolve?