thanks for the curl tip. I figured out that it was my fault. I had a wrong token so I got this reply from the telegram API:
curl --data chat_id=123456 --data-urlencode “text=Hello” “https://api.telegram.org/botWRONGTOKEN/sendMessage”
302 Found302 Found
nginx/1.9.1
Not the best error for a wrong token …