replace null check currentUser

static/src/app/services/login-service/login-service.ts

@@ -45,7 +45,10 @@ export class LoginService {
   }
 
   isLoggedIn() {
-    return localStorage.getItem('currentUser') != null;
+    if (localStorage.getItem('currentUser')) {
+      return true;
+    }
+    return false
   }
 
   hasPermission(level: number) {