Send origin header matching host to support cross-origin ws security
Send origin header matching host to support cross-origin ws security

**Why**
To support websocket servers which may implement this security recommendation:
https://en.wikipedia.org/wiki/Same-origin_policy#WebSockets

A more complete solution would involve creating an option in the Paho MQTT client for specifying a customer origin value.
The behavior in this commit would be the default if unspecified.
https://devcenter.heroku.com/articles/websocket-security#origin-header

**What**
- when connecting on ws:// or wss:// simulate the origin value a browser would send on the matching http origin.

choonkeat/paho.mqtt.golang,choonkeat/paho.mqtt.golang,choonkeat/paho.mqtt.golang