reduce connection timeout time from 5.0 to 0.5s, for detecting offline status for admins

I have no idea what the magic number "should" be, but 0.5s seemed better than 5 seconds (way too long).  Though the connection timeout is 0.5 seconds, when offline it takes longer than that to generate a timeout.

Note that in the case the connection times out, a page refresh might work.  This seems better than, on every request where the online status is checked, page load time is much longer.