Force http connection for user in multisite

Hello Good Day ,

I have wordpress network and one ssl certificate I just use ssl for my main domain administration

but my all user can connect https://*.site.com (wildcard) and get a error for unsecured ssl certificate

is not problem but google indexed some user page in https and visitors get a error and not enter to user website

I disable ssl for subdomain but main and subdomain directory the same and error stil work ,

How to I redirect subdomain for https conection to http

in wordpress , Sorry for very bad english