Revert "update stun server url."
Revert "update stun server url."

This reverts commit 73de749b7cce046b26123e2309175becb55fe27f.

komasshu-skyway-sample/plugins,komasshu-skyway-sample/plugins,alanmshelly/plugins,alanmshelly/plugins,yusuke84/plugins,yusuke84/plugins