فشل الترقية: مخرج "before-server" الخاص بـ Nginx مفقود... discourse_docker غير متوافق مع إصدار Discourse المختار

I’ve tracked down the issue — it was caused by the discourse-images-guardian plugin from @mbcahyono which needed the nginx.sample.conf file updating, I have done this and created a pull request to fix it.