Minor tweak.

examples/webgl_loader_msgpack.html

@@ -11,6 +11,9 @@ https://github.com/creationix/msgpack-js-browser
     <meta charset='utf-8'>
     <meta name='viewport' content='width=device-width, user-scalable=no, minimum-scale=1.0, maximum-scale=1.0'>
     <style>
+      body {
+        margin: 0px;
+      }
       #viewport {
         position: absolute;
         width: 100%;