How to always display the "advanced" panel on Firefox error screens

Question

Every time I get an error screen in firefox it is about a certificate problem. The dumbed down text that is show initially is utter useless (e.g. "Your connection is not secure. period.")

I find myself clicking the "Advanced" button all the time, because the reason for error is there (most of the time "certificate expired", or "self signed").

Firefox (and even IE) used to have a user-visible option to Not show simplified error messages. But this setting is gone from Firefox. This question is to ask if there is any hidden about:config entry that restore the sane behaviour of not hidding the useful information to save space when every screen have billions of pixels.