Making Firefox's title bar tall again on Mac

Some time back, Firefox decided to make their title bar short. As an aesthetic decision perhaps it made sense, and it does save a few pixels of real estate.

Recently, though, Apple continued with their habit of randomly changing things for no good reason and not giving people a means to revert. I hear it's a great way to cover up not actually having anything new to announce! On El Capitan, the old "maximize" button is now a "Take up the whole screen when that's obviously stupid because computers can do more than one thing at a time and we already had no trouble making things full screen for movies and the like" button.

Of course, Apple will helpfully point out that you can maximize by double-clicking on the title bar. The same title bar that Firefox made annoyingly short.
Annoyingly hard to click titlebar

This can be easily remedied. Go to about:config in the url bar (as pictured) and search for browser.tabs.drawInTitlebar. Double click it to make the value True, and enjoy your new, more clickable titlebar for easy maximization!