fix taiko test

test/taiko/apps.js

@@ -188,7 +188,7 @@ const assert = require('assert');
 
     // Zulip
     if (taikoTests.includes('zulip') || taikoTests === 'all') {
-      const dashboardUrl = 'https://zulip.' + domain
+      const zulipUrl = 'https://zulip.' + domain
 
       console.log('• Zulip')
       await goto(zulipUrl)