Minor change in "How to protect a website with Cloudflare without exp…

…osing ports to the Internet" (#840)

Fix #839

tutorials/cloudflare-website-protect/01.en.md

@@ -145,8 +145,7 @@ def get_cloudflare_ips(version):
     if response.status_code == 200:
         return response.text.strip().split('\n')
     else:
-        print("Failed to retrieve Cloudflare IP ranges")
-        return []
+        raise Exception("Failed to retrieve Cloudflare IP ranges", response)
 
 def whitelist_ips_in_hetzner(ip_ranges):
     headers = {