[-] BO : Fixed bug to update image legend on AdminProduct

Methods to update legend for product image on Backoffice (bug since 1.5 launch). Needed the tpl change in another Pull Request
Hi,

Thank you for your PR but sorry we can not merge this like it. It does not follow our current code norms.

http://doc.prestashop.com/display/PS15/Coding+Standards

Regards