Domain Mapping and SSL problems with subdomains

I have a single site SSL certificate that is only active on my primary domain, adefiniteplan.com. When I create the subdomains in multisite, they are not available for the SSL certificate, but when I try to go to wp-admin (example: entrepreneuruniversity.adefiniteplan.com/wp-admin), it tries to force HTTPS. How can I block HTTPS on all subdomains?