Fix typo

src/materials/MeshPhongMaterial.js

@@ -41,7 +41,7 @@ import { Color } from '../math/Color.js';
  *  alphaMap: new THREE.Texture( <Image> ),
  *
  *  envMap: new THREE.CubeTexture( [posx, negx, posy, negy, posz, negz] ),
- *  combine: THREE.Multiply,
+ *  combine: THREE.MultiplyOperation,
  *  reflectivity: <float>,
  *  refractionRatio: <float>,
  *