Display edge redirect notice in timeout pages

[Diogo Matsubara]

A notice for beta testers is displayed in Launchpad's home page <https://launchpad.net/> telling them that they will be automatically redirected to edge and offering an option to disable this redirection for 2 hours.

We want to display a similar notice in time out pages, so people that are affected by a timeout on edge can revert back to production on the spot.

[Diogo Matsubara (matsubara)]

I have a initial implementation but I'm having problems testing this properly.

Running xx-beta-testers-redirection.txt I get the following output:

https://pastebin.canonical.com/14066/

Checking the OOPS generated <https://pastebin.canonical.com/14065/> one can see that there wasn't a logged in user.

So the +soft-timeout page times out before it has a chance to figure out who's the logged in user and display the edge redirection notification.

[Diogo Matsubara (matsubara)]

This investigation also reminded me of a similar problem we had in the past, which led us to simplify the oops and timeout templates to not include information about the logged in user.

[Diogo Matsubara (matsubara)]

Fixed in devel r8195