Adds aluebs@webrtc.org as owner to audio_processing

BUG=N/A
TESTED=trybots
R=tina.legrand@webrtc.org

Review URL: https://webrtc-codereview.appspot.com/17709004

git-svn-id: http://webrtc.googlecode.com/svn/trunk@6445 4adac7df-926f-26a2-2b94-8c16560cd09d