Single click open URLs in urlgrabber

One of the most annoying things about switching to hexchat is that you can't single click links to open them. Whenever I try to open a url, I always fumble around trying some combination of clicks until the thing finally works.

This makes urls also open with a single click, which makes everything much more bearable for me. It may be useful for other people.

I don't know if this is a sort of patch that you accept, or if there's a more standard way to do this sort of patch.