bug report: inaccurate thumbnail bug - modulargrid

ModularGrid is a site used by synthesizer enthusiasts to store and share their rack configurations.  When a new rack is created and shared in Discord chat, the thumbnail which appears is accurate.  Thereafter however the thumbnail never updates.  This means no one can tell the configuration without clicking through.  

Suggested fix: when a modulargrid URL is posted, check for an updated thumbnail.

random example rack: https://www.modulargrid.net/e/racks/view/1634208

List of all public racks: https://www.modulargrid.net/e/racks