icecandidate (srflx) was not pick up as local-candidate

[LeZhang Gu]

Hi, team

I use webrtc-internals as a tool to trace a connection fail issue.

I found that during connection try to establish, it has a srflx from STUN server. But was not pick as a local-candidate

Here is the candidate grip. Only remote-candidate have srflx but local-candidate without srflx. And this is the root cause of connection fail