fix(BeatLeader): fix broken regexp

[joerkig]

Description

Hopefully makes the RegExp of the BeatLeader presence not inject into every website that ends in .net

Acknowledgements

• [x] I read the Presence Guidelines
• [x] I linted the code by running yarn format
• [x] The PR title follows the repo's commit conventions

Screenshots

Proof showing the creation/modification is working as expected