don't say logged out if you weren't logged in

[prateek032]

steps to replicate:

1. Create a notebook and publish it
2. Logout and open the published notebook in view.html mode
3. Now click on edit icon
   session reconnect message appears and in URL it shows "notebook=null".

[gordonwoodhull]

Since the notebook=null is not reproducible, I'm going to repurpose this issue.

It should not say you've been logged out, it should send you directly to login.R if running view.html notebook anonymously and press edit button.

[gordonwoodhull]

Duplicate of #1923