[horde] Link only valid for 30 minutes behavior with log out

[Kareem Dana]

If I'm logged into horde, but idle for a while then come back and hit log
out. I get the following message:

This request cannot be completed because the link you followed or the form
you submitted was only valid for 30 minutes. Please try again now.

I understand the reason for having this when someone has been idle for a
while, but I think when they hit log out and only log out, horde should log
the user out regardless. Instead, it refreshes my session and I'm back to
fully logged in and have to hit log out a second time. It can even improve
security if a user hits log out, just assumes it will log them out and
either leaves the pc right away or doesn't pay attention to what page loads
next. I've done that from time to time. Any thoughts on this?