bug#52393: pdf links not clickable when zathura is launched via xdg-open

[bdju]

Okay, disregard. It seems a double-click is required rather than a
single click, and it takes about 5 seconds for anything to happen. I was
possibly clicking a different number of times between tests. Maybe I was
more desperate when I launched with zathura explicitly. It seems to work
the same both ways now.