Fix: contact_changed event to get the correct newId and oldId

[khsoh]

PR Details

The newId and oldId returned by the contact_changed event was incorrect for an individual chat.

Description

My bot received a contact_changed event. The oldId and newId were incorrect. After I had dumped out the message, I noted where these fields could be retrieved

Related Issue(s)

Motivation and Context

Fix newId and oldId for contact_changed event

How Has This Been Tested

Environment

• Machine OS:
• Phone OS:
• Library Version:
• WhatsApp Web Version:
• Puppeteer Version:
• Browser Type and Version:
• Node Version:

Types of changes

• Dependency change
• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to change)

Checklist

• My code follows the code style of this project.
• I have updated the documentation accordingly (index.d.ts).
• I have updated the usage example accordingly (example.js)

[purpshell]

needs testing