30' timeout on mail redaction

[mmallejac]

We've noticed today a strange behavior : we've left open a new email for 30 minutes (busy at something else !) and when we wanted to finish writing this mail and send it, impossible:

If we press Stay on page, then:

And if we press leave page:

[the-djmaze]

I know what is happening.
Sometimes "auto logout" occurs and then the application is stall.

I still need to figure out what to do on popups and such

[the-djmaze]

This commit might solve it e07749b