Use exec for proper SIGTERM handling

start.sh

@@ -86,4 +86,4 @@ echo "=> Updating nodebb"
 /usr/local/bin/gosu cloudron:cloudron node /app/code/app --upgrade
 
 echo "=> Starting nodebb"
-/usr/local/bin/gosu cloudron:cloudron node /app/code/loader.js --no-daemon --no-silent
+exec /usr/local/bin/gosu cloudron:cloudron node /app/code/loader.js --no-daemon --no-silent