Only send video in gocv-receive

Pion now implicitly creates transceivers when answering. Before we would
ignore audio, now we need to explicitly not send it.

Author: Sean-Der

gocv-receive/README.md

@@ -18,7 +18,7 @@ go get github.com/pion/example-webrtc-applications/gocv-receive
 ```
 
 ### Open gocv-receive example page
-[jsfiddle.net](https://jsfiddle.net/b3d72av1/) you should see your Webcam, two text-areas and a 'Start Session' button
+[jsfiddle.net](https://jsfiddle.net/Lsfkexmt/) you should see your Webcam, two text-areas and a 'Start Session' button
 
 ### Run gocv-receive with your browsers SessionDescription as stdin
 In the jsfiddle the top textarea is your browser, copy that and:

gocv-receive/jsfiddle/demo.js

@@ -11,7 +11,7 @@ var log = msg => {
   document.getElementById('logs').innerHTML += msg + '<br>'
 }
 
-navigator.mediaDevices.getUserMedia({ video: true, audio: true })
+navigator.mediaDevices.getUserMedia({ video: true, audio: false })
   .then(stream => {
     pc.addStream(document.getElementById('video1').srcObject = stream)
     pc.createOffer().then(d => pc.setLocalDescription(d)).catch(log)