Disallow using discord cdn links because they expire

[MineKing9534]

Checklist

• [x] Read Contribution Guidelines and Style Guides
• [x] Test the Code
• [x] This PR is ready to review and merge

Description

This disallows using discord cdn links as background url for rank cards because they will no longer works after 2 weeks because of expiry

Other Information

See https://discord.com/channels/1077255218728796192/1077261949357797386/1276236467588563106