Error in upgrading-deis.rst

[aledbf]

In the docs this is the procedure to do a manual update:

$ ssh core@
$ sudo su
$ echo GROUP=stable > /etc/coreos/update.conf
$ systemctl unmask update-engine.service
$ systemctl start update-engine.service
$ update_engine_client -update
$ systemctl stop update-engine.service
$ systemctl mask update-engine.service
$ reboot

this is wrong (at least now).
Why? coreos/bugs#262

the boot partition is updated after the reboot so if the update-engine service is disabled it will not run and update the boot flags.
Only after this output from journalctl -u update-engine.service
[0226/232543:INFO:update_attempter.cc(674)] Updating boot flags...
is safe to disable the update-engine service. (after the next update it will use the updated version)

This means that https://github.com/deis/deis/blob/master/contrib/coreos/user-data.example#L25 must be remove so after the reboot with the update update-engine.service will start automatically

reference coreos/bugs#262

[carmstrong]

Thanks @aledbf. So we have to somehow allow it to run once after a reboot before disabling it? That sounds difficult :(