fix typo

examples/js/loaders/GLTFLoader.js

@@ -841,7 +841,7 @@ THREE.GLTFLoader = ( function () {
 
 				for ( var i = 0, il = params.length; i < il; i ++ ) {
 
-					target[ params[ i ] ] = source[ params[ i ] ];
+					var value = source[ params[ i ] ];
 					target[ params[ i ] ] = value.isColor ? value.clone() : value;
 
 				}