title: telegram doesn't show the image preview link always
body: <p>I use the following code to send a message that contains both text and image. in order to show the image i used link preview to show the images, but almost every 15 message, 2 of them have no image preview whereas their image link is shown by browser (i mean no problem with the link) and the rest of the messages show both text and image preview with no problem. where is the problem?</p>
  
  <pre><code>&lt;?php
  
  
  $message = the message
  $img = img_link
  
  $message_="
  &lt;a href='$img'&gt;&amp;#8205;&lt;/a&gt;
  $message
  ";
  
  $ch = curl_init();
  curl_setopt($ch, CURLOPT_POST, true);
  curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);
  curl_setopt($ch, CURLOPT_HTTPHEADER, ['Content-Type: multipart/form-data']);
  curl_setopt($ch, CURLOPT_URL, 'https://api.telegram.org/bot'.$botToken.'/sendMessage');
  $data = array(
      'chat_id' =&gt; $chat_id,
      'text' =&gt; $message_,
      'parse_mode' =&gt; 'HTML',
      'disable_web_page_preview' =&gt; false,
  );
  curl_setopt($ch, CURLOPT_POSTFIELDS, $data);
  $res=curl_exec($ch);
  
  ?&gt;
  </code></pre>