fix wrong map usage

Author: 100gle

static/js/passedState.js

@@ -28,13 +28,14 @@ class PassedState {
     _prepareState(rawState) {
         const state = new Map();
         for (const level in rawState) {
-            state[level] = [];
+            const challenges = [];
             for (const challengeName of rawState[level]) {
-                state[level].push({
+                challenges.push({
                     name: challengeName,
                     passed: false
                 });
             }
+            state.set(level, challenges);
         }
 
         return state;