Added recommended settings for hitbox.tv

hitbox.tv wants CBR and a Keyframe Interval of 2 seconds according to
their website.

They also don't like mp3.
(OBS does currently not have a warning for mp3 only.)

http://help.hitbox.tv/customer/portal/articles/1430057-what-are-the-prefered-settings-in-my-streaming-software-to-use-with-hitbox-
Updated hitbox.tv ingest server list

apac and lax resolve to the same ip adresses.
The hitbox.tv API says lax for Asia.