[BUG] Sites with non-absolute paths to favicons don't load

[jaden]

Describe the bug

Sites that have favicon link href's using a relative or absolute path without a domain don't load.

Examples:

• https://www.androidpolice.com/ - uses absolute path with no host: /public/build/images/favicon-48x48.5475dbfb.png
• https://www.synology.com/en-us/company/news - uses base element with relative path: img/icon/touch-icon-57.png

To Reproduce
Steps to reproduce the behavior:

1. Subscribe to one of the above sites
2. Instead of showing the site's favicon on feed items, it shows the generic one.

Expected behavior
The favicon referenced on the site should be shown.

Environment information (please complete the following information):

• Device: Any
• OS: Any
• Browser: Any
• FreshRSS version: 1.22.1
• Database version: SQLite
• PHP version: PHP 8.2
• Installation type: Manual

Additional context
I've been testing a fix that has worked on all of the sites I've tested it with. I'll submit a PR.