[-] MO: fix a problem with the wishlist_link

With @ArtDesign, we see that if you put the module "Block MyAccount" before the "Wishlist", the wishlist_link var is not declare yet, so the link is empty. If you put the var in the header, it can be accessed by the other tpl.

Or, we can put this in a {$link->getModuleLink(...)} in TPL
Merge pull request #222 from PrestaEdit/patch-17

[-] MO: fix a problem with the wishlist_link