Since accidentally joining a server wastes a lot of time, i don't think this is a good idea. Also the de facto standard is for double clicking an entry to refresh the status of that server.
Accidentally joining a server would be a pain, but how often would you expect it to happen? I could see it happening a lot if it were just one click, but accidentally clicking twice on one spot fast enough for it to register as a double click seems rather farfetched.
On a related note, I've never used a server browser in which double clicking refreshed the status of the server rather than joining it.