infinite loop in a WebHook
<p>I'm doing a facebook messenger bot. After you start it, it makes a call to WebHook. 
Unfortunately after the first start will not stop throwing the same call with the same parameters.
The settings are:</p>

<ul>
<li>message_deliveries;</li>
<li>message_reads;</li>
<li>messages;</li>
<li>messaging_optins;</li>
<li>messaging_postbacks.</li>
</ul>

<p>The source code is this: <a href="https://github.com/Ellusu/nuraghebot-facebookmessenger/blob/master/index.php">https://github.com/Ellusu/nuraghebot-facebookmessenger/blob/master/index.php</a></p>

<p>Where am I wrong?
Why does only one call?</p>