Attachment blocked by Chrome

Hello,
my xwiki is in 14.10.14
My issue: in Chrome, when I click on an attachment, nothing happens and I have the following message in the downlad view “Non secure download blocked” ( it’s a translation from French)

it seems it happens because xwiki generate a link beginning in “http” instead of “https” ?
Even when I disable the security check in Chrome, it’s the same.
This problem doesn’t happens on Safari and Firefox.
What can I do ? Is it possible to configure xwiki to generate a https link instead http when I clic on an attachment? Will it solve my issue ?
Thanks
Catherine