Get rid of the pubnub warning message and set the default origin to "pub...

<h2>ABSTRACT:</h2>

Get rid of the pubnub warning message and set the default origin to "pubsub.pubnub.com".
See also: <https://help.pubnub.com/entries/21403311-How-Do-I-Use-a-Custom-Origin->.

<h2>REVIEWER(S):</h2>

@larsxschneider 

<h2>TESTING:</h2>

Manual testing.

Can't we just set the `_DEBUG` in our code? I would like to merge only changes that could eventually go upstream.
@Kosta-Github what do you think?