This web site has been upgrade to use https secure access versus the older and non encrypted http.
There is nothing here that is controversial or secret that needs protection. However, Google announced some time ago that it would downgrade search results for content that is not accessible via https.
In effect, Google is forcing even hobby web sites to obtain digital certificates, which are marketed more for business use than personal use and can cost a substantial sum, for each web site you run. Today, there are less costly options available such as from https://www.sslforfree.com where obtained a valid certificate – with the caveat that the free certificate needs to be renewed every 3 months.
All access to the http://3d.coldstreams.com address will automatically translate to https://3d.coldstreams.com.
Visitors to the web site should not see any changes except that Firefox may issue a minor warning that some linked content on the page is to non-secure web sites.