When using /sockopen -e with SSL on 7.35, mIRC warns you if the certificate is 'unknown'. I think that wasn't happening before, if it's an intentional change, we would need something to bypass that warning.
Also, if you tell it to remember the decision for the future, it doesn't remember it
To reproduce, //sockopen -e test dl.dropboxusercontent.com 443 with ssl available. result: