provide sign-in over secure connection

[rpr]

Hi!

Although this site is available over HTTPS (https://w3schools.invisionzone.com) I notice that many site links I follow (e.g. "sign in" and "create new topic") open pages over HTTP.

This is especially problematic for sigh-in form which means that user credentials will be sent to the server over insecure connection. Firefox gives an appropriate warning in such a case.

Please fix this ASAP.

-- rpr.