Log out current session after logging in in different tab

The QA team asked about the following sequence:

> - Open 2 tabs
> - Log in as a first user
> - Log out (the user should be logged out in both tabs)
> - Log in again in the first tab as a first user
> - Go to the second tab and try to log in using a different account- second user
> - The user sees, "A user is already logged in. Please refresh the page to continue."
> - Refresh the page manually
> - As a result of refreshing the page the user is logged in as the first user, not the second user (the email and password that was typed in in log in fields)

This is the expected behavior at the moment. However, I do think that this sequence can be confusing. Even if you aren't trying to log in as a different user, it is probably confusing to be told to refresh the page in order to log in. @lognaturel wrote:

> I do agree it would be more helpful for the second login attempt to log the first user out and then complete.

Note that seeing that message is possible even if there aren't currently two open tabs:

- Open two tabs, navigating to login.
- Log in in one tab, then close the tab.
- Submit the login form in the second tab.