Comment 9 for bug 2115

I've tweaked the description because it was inaccurate (we restart LP very often - the session database is persistent). That said, while I can imagine possible improvements here, dealing with anonymous POST is really very tricky, and I think we're better off not doing that on the server side: better for client browsers to let users retry (which they do) - and the user to just log in in another tab and hit the retry button on their browser.