It's getting to be quite an annoyance
Not possible as far as I know.
Why would they not include an option for this??
Maybe try complaining to the site your trying to login to and ask them to make their login HTTPs instead of HTTP only
Yeah, complaining to each of those sites individually sure seems like a worthwhile effort instead of just seeing if the browser has such a simple option.
In this day and age, the amount of security for an account provided by an insecure log-in mechanism is minimal. Asking a browser maker to provide a bypass for their security design is like asking an auto designer for a bypass switch for the seatbelt warning system. It's unsafe, and it's unlikely to happen. Even if some other browsers have work-arounds to allow insecure log-ins, they are only dodging the issue: if a site requires log-in, it implies the account is something that should be protected via a hidden username and password. Allowing that information to be sent in the clear where it can be intercepted and read in many different ways undercuts the whole purpose of requiring the log-in in the first place. Even if the sites are numerous, they are the ones weakening user log-in security by requiring insecure log-ins.
Let's put it this way ... Chrome has no option to disable it either. If they can't or won't fix their site, all Chrome users will see a warning too.
@blackbird71 It would be more akin to asking a bike manufacturer to have an option to remove the safety wheels off of your bike.