fix(curriculum): consts must be initialized

curriculum/challenges/english/02-javascript-algorithms-and-data-structures/basic-javascript/accessing-object-properties-with-variables.md

@@ -108,7 +108,7 @@ const testObj = {
 };
 
 // Only change code below this line
-const playerNumber;       // Change this line
+const playerNumber = 42;  // Change this line
 const player = testObj;   // Change this line
 ```