title: Prestashop 1.7.4.x - Missing variables values when using order_conf as new email template
body: <p>I have missing variables when using a new email template. 
  I have not changed any core code for this email template. </p>
  
  <p>Is anyone can help me on this ?
  [ I'm using Prestashop 1.7.4.x ]</p>
  
  <p><a href="https://i.stack.imgur.com/lgxPe.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/lgxPe.png" alt="enter image description here"></a></p>
  
  <p><a href="https://i.stack.imgur.com/cyjWR.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/cyjWR.png" alt="enter image description here"></a></p>