Added community.sitecore.com to CSP img-src directive

[gkLeo]

Description / Motivation

Added https://community.sitecore.com to the CSP img-src directive to fix avatar photo blocking. Avatar images from community.sitecore.com were being blocked by the Content Security Policy, causing profile photos to fail to load on MVP profile pages.

Related Issue: #593

How Has This Been Tested?

1. Navigate to a profile page that displays avatar photo from community.sitecore.com
2. Verify that avatar images load successfully without CSP violations in the browser console

Types of changes

• 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:

• I have read the Contributing guide.
• My code/comments/docs fully adhere to the Code of Conduct.
• My change is a code change.
• My change is a documentation change and there are NO other updates required.