Update aws-waf.md

[JV0812]

Purpose of this pull request

This pull request is to update the existing image tag error.

Select the type of change

• Minor Changes - Typos, formatting, slight revisions
• Update Content - Revisions, updating sections
• New Content - New features, sections, pages, tutorials
• Site and Tools - .clabot, version updates, maintenance, dependencies, new packages for the site (Docusaurus, Gatsby, React, etc.)

Ticket (if applicable)

[kimsauce]

Thanks for doing this, @JV0812 ! I'll go ahead and merge it since it's a straightforward fix.