remove quickshare demo link (error 503)

- ref. https://github.com/awesome-selfhosted/awesome-selfhosted/issues/2266

README.md

@@ -950,7 +950,7 @@ Simplified file servers for sharing of one-time/short-lived/temporary files, pro
 - [Pomf](https://github.com/Pomf/Pomf) - Pomf is a simple file uploading and sharing platform. `MIT` `PHP`
 - [ProjectSend](https://www.projectsend.org/) - Upload files and assign them to specific clients you create. Give access to those files to your clients. ([Source Code](https://github.com/projectsend/projectsend)) `GPL-2.0` `PHP`
 - [PsiTransfer](https://github.com/psi-4ward/psitransfer) - Simple open source self-hosted file sharing solution with robust up-/download-resume and password protection. `BSD-2-Clause` `Nodejs`
-- [QuickShare](https://github.com/ihexxa/quickshare) - Quick and simple file sharing between different devices. ([Demo](https://hexxa-quickshare.herokuapp.com/)) `LGPL-3.0` `Go`
+- [QuickShare](https://github.com/ihexxa/quickshare) - Quick and simple file sharing between different devices. `LGPL-3.0` `Go`
 - [Share](https://github.com/MrDemonWolf/share) - Simple yet advanced uploader - upload files, images and text with moderation tools for admins. Can be used for friends and family or just for you. Integration with ShareX and more. `MIT` `Nodejs`
 - [Sharry](https://github.com/eikek/sharry) - Share files easily over the internet between authenticated and anonymous users (both ways) with resumable up- and downloads. `GPL-3.0` `Scala/Java`
 - [Snapdrop](https://snapdrop.net/) - Local file sharing in your browser. Inspired by Apple's Airdrop. ([Source Code](https://github.com/RobinLinus/snapdrop)) `GPL-3.0-only` `Docker`