message: style: update window design
  use more rounded corners
diff: @@ -30,6 +30,7 @@ body.jsxc-fullscreen {
  .jsxc-window {
  background-color: #d4d2d2;
  border: 0;
  + border-radius: 0;
  left: 0;
  position: absolute;
  right: 0;
  