Add proto.xml to .gitignore (and alphabetize).

TBR=henrika@webrtc.org

Review URL: https://webrtc-codereview.appspot.com/868014

git-svn-id: http://webrtc.googlecode.com/svn/trunk@2922 4adac7df-926f-26a2-2b94-8c16560cd09d
1 file changed