message: fix: print user media error to console
  in debug dialog
diff: @@ -29,9 +29,11 @@ export default function() {
  UserMedia.request(['video']).then(stream => {
  VideoDialog.attachMediaStream(videoElement, stream);
  }).catch(err => {
  + Log.warn('Video request failed.', err);
  +
  videoElement.remove();
  - dom.find('.jsxc-webcam').append(err);
  + dom.find('.jsxc-webcam').append(err.toString());
  })
  });
  