Got it. Yep, I can confirm that the dictionary dosn't work for some reason. Looks like LEO site uses a lot of javascript/ajax to load the content and for some reason decides not to return the translations when the URL is opened from within GoldenDict.
Interestingly enough, when I save the page (via F2) and open in Chrome browser, it works just fine and loads the content.
Some more investigation is needed.
I've filed an issue for this problem:
https://github.com/goldendict/goldendict/issues/346