Hello,
on my website : wallstock.fr , some pages are indexed by the search engines with https then that I never activated the security certificate.

The setting in the security page is http and the database table options is also http .

someone has an idea where the problem could come from ?

Not really. Does your server support or has https enabled? I think Google at least forces to use https if available nowadays. So maybe it just tries it independent from Zenphoto's setting (which https on the server is actually)?

hello acrylian

it is a shared server but from the host (OVH) https is not enabled on my space

on last month, one page has been indexed https, other normally indexed http .

I do not know if this fact is related but less quickly google indexes my pages

Sorry, I have no idea. Google normally follows just links to index, both on the site or via a xml sitemap. I have no idea why it would use https if none of these links are in use.