[BUG] v7.3 mdi icons not working by v6 OK

**Deployment details:** - App version [e.g. v1.7.4]: v2.3.1 - Platform [e.g. amd64, arm64, arm/v7]: uraid docker image by pawelmalak - Docker image tag [e.g. latest, multiarch]: latest --- **Bug description:** A clear and concise description of what the bug is. v7.3 icons from https://pictogrammers.com/library/mdi/ do not show up corrected in Flames. v6 icons are fine. --- **Steps to reproduce:** 1. add a new menu item 2. click on "click here for reference" to find an icon 3. add any v7.3 icons, example, generator-portable or power-plug-battery, icon will not show up 4. add any v6 icons, example, home-battery, icon will show up in flame menu correctly