ShaderLib: Minor code clean up.

src/renderers/shaders/ShaderLib.js

@@ -172,10 +172,10 @@ THREE.ShaderLib = {
 		fragmentShader: [
 
 			"uniform vec3 diffuse;",
-			"uniform float opacity;",
-
 			"uniform vec3 emissive;",
 
+			"uniform float opacity;",
+
 			"varying vec3 vLightFront;",
 
 			"#ifdef DOUBLE_SIDED",