Oops! Looks like Firefox will be going this way at the end of June. See:
https://addons.mozilla.org/en-us/firefox/addon/disable-dhe/

My Firefox is at version 38.0.5, and I can still connect to Freephoneline.ca site normally. But I still cannot connect with Opera.

Opera is trying to be a nanny-browser when no one asks it to. Logjam is not an easy exploit to, well, exploit, and it's not like I'm trying to connect to a compromised banking site. With this enforcement policy, Opera found a way to drive its single-digit market share even lower.

Every good security policy states that at the end of the day security should be in the hands of customers. The product must provide all the tools to enable "perfect" security and flag all known issues, but it must be up to the end user to make the ultimate decision whether to take a perceived risk.

Here you are: https://www.freephoneline.ca

Surprisingly enough, this site allows for a non-encrypted http connection (that's bad!), and Opera is perfectly OK with it...

Starting in Opera 30, Opera prevents the HTTPS connection to servers with the D-H group lower than 1024 bits (susceptible to "logjam" attacks). When attempted to connect, you receive this message:

"Server has a weak ephemeral Diffie-Hellman public key.
This error can occur when connecting to a secure (HTTPS) server. It means that the server is trying to set up a secure connection but, due to a disastrous misconfiguration, the connection wouldn't be secure at all!
In this case the server needs to be fixed. Opera won't use insecure connections in order to protect your privacy."

This is nice, but there needs to be a way (via developers flags, for example) to disable the enforcement. I am aware of weakened security for some sites but need to connect to them anyways - locking the users out is not a solution because we do not control the server settings! Warning is fine, but locking out is unacceptable - besides, on some sites I may not even care that much about perfect security in the first place.

Is there a workaround solution to get around this - short of downgrading to Opera 29, or using other browsers, ALL of which still allow the connections (at least for now)?