Update demos to have local audio control muted by default.
Review URL: https://webrtc-codereview.appspot.com/1160007

git-svn-id: http://webrtc.googlecode.com/svn/trunk@3649 4adac7df-926f-26a2-2b94-8c16560cd09d
diff --git a/samples/js/demos/html/pranswer.html b/samples/js/demos/html/pranswer.html
index eb807a2..ba1949e 100644
--- a/samples/js/demos/html/pranswer.html
+++ b/samples/js/demos/html/pranswer.html
@@ -11,7 +11,7 @@
   </style>
   </head>
   <body>
-    <video id="vid1" autoplay></video>
+    <video id="vid1" autoplay="true" muted="true"></video>
     <video id="vid2" autoplay></video>
     <br>
     <button id="btn1" onclick="start()">Call</button>