P2P Chat video blackout when interrupted by 3rd party request

[jerrychabolla]

Bug happens when 2 users are in a P2P chat, and a 3rd user requests to chat with one of them, their remote users video goes black upon receiving the request even though the 3rd party request was not responded to.

Reproduce:

Setup webrtc.html in examples folder

1. Open 3 browser windows
2. Sign in each one with user 1, user 2 and user 3 respectively.
3. Make user 1 call user 2 to create a Peer conversation.
4. Have user 3 call user 1 for a peer conversation. Upon canceling the request of user 3 user 1 will no longer see user 2 video, but user 2 will continue to see user 1.

Tested on Chrome Version 47.0.2526.73 (64-bit)