No error message displayed in Walkthrough Web Sample

• Type: Bug
• Status: Closed
• Resolution: Fixed
• Affects Version/s: Master
• Fix Version/s: 7.4.3.29 CE GA29, 7.4.3.30 CE GA30, Master
• Component/s: JS APIs and Utilities
• Labels:
  • 7.4.13-u29
  • liferay-update-dxp-29-7413
• Fix Priority: 3
• Sprint: Lima | QA Sprint 21
• Git Pull Request: https://github.com/liferay-frontend/liferay-portal/pull/2295

Steps to Reproduce:

1. In SampleWalkthrough.js create another JSON step
   • ex. 

     {
     	content: '<span>Content 6</span><br/><code>Hello6</code>',
     	nodeToHighlight: '#step6',
     	positioning: 'bottom',
     	title: 'Title 6',
     },
      

1. Deploy frontend-js-components-sample-web to a test page
2. Navigate to the Walkable tab on the sample portlet
3. Click on the Hotspot (blue dot) and click through all the steps to the last step with no element

Expected Result:
An informative error message regarding no element exists displayed on JS console
Walkthrough component UX is still present (either hotspot or popover mode)

Actual Result:
Generic error is thrown in Chrome's devtool console.

Reproduced on:
Tomcat 9.0.56 + MySQL 5.7
Portal master GIT ID: bfac03e8e77bc65cecc9709ecfe642f071fb3476