Localization for google recaptcha in contact form

[LesGiroiseaux]

Good morning everyone,

I would need your help to configure this option.

I am not a prestashop developer, but a software programmer in other domains, so I can follow technical suggestions :). 

I was able by following suggestions in the forum to add the Google recaptcha v2 to my website, and it works properly.

I am using Prestashop 1.6.24

What I did is 

- include in header.tpl the following code, specifying the language "French" as default

<script src='https://www.google.com/recaptcha/api.js?hl=fr'></script>

- add the recaptcha module in contact_form.tpl as follows

<div class="g-recaptcha" data-sitekey="MY_PERSONAL_SITE_KEY"></div>

and finally, I check for a valid captcha in ContactController.php.

My problem is that my website is available in 4 languages, and the captcha is always shown in the language I select at the beginning.

I see that in the contact_form.tpl module, the text is modified depending on the selected language (informations like "Send a Message", "Order reference" and so on), so my question is: would it be possible to modify the captcha language parameter dynamically from contact_form.tpl? Or, would it be possible to do so already in header.tpl (I assume that the user already has its language configured)? How could I obtain the language information at this stage?

Thanks to everyone willing to help!