Fix bug when loading hand controls model and accessing the material. Introduced after bumping THREE to r152

Author: dmarcos

src/components/hand-controls.js

@@ -206,7 +206,7 @@ module.exports.Component = registerComponent('hand-controls', {
         self.clips = gltf.animations;
         el.setObject3D('mesh', mesh);
 
-        var handMaterial = mesh.children[1].material;
+        var handMaterial = mesh.children[0].material;
         handMaterial.color = new THREE.Color(handColor);
         mesh.position.set(0, 0, 0);
         mesh.rotation.set(handModelOrientationX, 0, handModelOrientationZ);