Examples: Use MeshNormalMaterial again in webgl_instancing_suzanne.

examples/webgl_instancing_suzanne.html

@@ -39,7 +39,7 @@
 					geometry.computeVertexNormals();
 					geometry.scale( 0.5, 0.5, 0.5 );
 
-					var material = new THREE.MeshStandardMaterial( { metalness: 0 } );
+					var material = new THREE.MeshNormalMaterial();
 					// check overdraw
 					// var material = new THREE.MeshBasicMaterial( { color: 0xff0000, opacity: 0.1, transparent: true } );