Bye request should use POST not GET
Bye request should use POST not GET

AppRTCDemo is failing to cleanly exit a room because it sends a GET request to /bye. The request to /bye should be a POST request. Because the /bye request is failing, the room is still marked as "full" and rejoining will fail.

BUG=
R=tkchin@webrtc.org

Review URL: https://webrtc-codereview.appspot.com/47759004

Patch from Chuck Hays <haysc@webrtc.org>.

Cr-Original-Commit-Position: 972c6d2dc6dd5efdad1377c0d224e03eb8f276f7@{#8860}
Cr-Mirrored-From: https://chromium.googlesource.com/external/webrtc
Cr-Mirrored-Commit: caae5d47c1d7a479955a3445ff9e7c48de59a168

sippet/talk,sippet/talk,sippet/talk,sippet/talk,sippet/talk