CP Avatars sometimes appearing with double slash

[dougblackjr]

Description of the problem

We hosted our avatars on a CDN. We have the avatar path set to the Cloudfront path in the config.php, which is working fine.

On the backend, we are seeing an additional slash getting added to the avatar path. The double slash is breaking the avatar call through the CDN since CF doesn't know how to process it.

How To Reproduce

Steps to reproduce the behavior:

1. Set avatar path to use Cloudfront or other CDN.
2. Set avatar

Error Messages

No error, just a broken image.

Environment Details:

• Version: 7.4.x
• PHP Version 8.1
• MySQL Version 8.x
• OS: Linux
• Web Server: nginx

Possible Solution

Add checks for slash and add them manually.

Additional context

PR incoming.