Don't require click when capturing whole desktop

[OttoAllmendinger]

See comment by by KiraaCorsac in the comments:

Also, is the click after screenshoting the whole desktop neccesary? I usually want shot of the desktop I pressed the screenshot button on. I managed to comment it out of the code, but I think more people would appreciate at least a switch for the unnecessary click.

I think I originally left it in because otherwise the menu would be visible on the screenshot. But a better way would be to hide the menu before making the screenshot (if the event was triggered from the menu at all)