[HTTPS-Everywhere] What's the preferred means to refresh or reload the rulesets without restarting Firefox?

[J.B. Nicholson]

I vaguely recall that there used to be a binary preference in Firefox one 
could find with about:config, toggle it twice, and the rulesets were reloaded.

I don't recall which preference that was, and 
https://www.eff.org/https-everywhere/rulesets and 
https://www.eff.org/https-everywhere/faq aren't helping me identify that 
preference. Which preference was/is this?

Now that WebExtensions are the way of things, what is the preferred way to 
refresh or reload the rulesets using Firefox without restarting Firefox?

Thanks.