Fix computed property example

I'm sure the fruit variable was supposed to be used somewhere.

1-js/04-object-basics/01-object/article.md

@@ -189,7 +189,7 @@ We can use more complex expressions inside square brackets:
 ```js
 let fruit = 'apple';
 let bag = {
-  ['apple' + 'Computers']: 5 // bag.appleComputers = 5
+  [fruit + 'Computers']: 5 // bag.appleComputers = 5
 };
 ```