Note: After saving, you have to bypass your browser's cache to see the changes. Internet Explorer: press Ctrl-F5, Mozilla: hold down Shift while clicking Reload (or press Ctrl-Shift-R), Opera/Konqueror: press F5, Safari: hold down Shift + Alt while clicking Reload, Chrome: hold down Shift while clicking Reload.
mw.loader.using("mediawiki.user",function(){if(mw.user.options.get('compact-language-links')!=='0'){(newmw.Api()).postWithToken('options',{action:"options",change:"compact-language-links=0"}).done(function(){mw.loader.using([],function(){mw.notify("Compact language links has been turned off. Please refresh the page.");});});}else{console.log('Compact language links has been already turned off.');}});