How to avoid the power button menu in ubuntu 14.04 and go straight to hibernate

I see that Trusty Thar is starting to use systemd (which I don't know much about) and, specifically, the power button in the notebook is handled by it.

Whenever I press the power button I get a graphical menu like the one in https://drive.google.com/file/d/0B2SULlYgDhZbaDJwMDZXOVA2WlU/view (sorry for the crappy phone photo, but can't screenshot when the menu is displayed).

I'd like the power button to go straight to hibernate without asking for other options or permission. Googling around, I found about /etc/systemd/logind.conf and changed a few options (see below), but the behavior stays the same.

My current /etc/systemd/longd.conf says:

[Login]
#NAutoVTs=6
#ReserveVT=6
#KillUserProcesses=no
#KillOnlyUsers=
#KillExcludeUsers=root
Controllers=blkio cpu cpuacct cpuset devices freezer hugetlb memory perf_event net_cls net_prio
ResetControllers=
#InhibitDelayMaxSec=5
HandlePowerKey=hibernate
HandleSuspendKey=suspend
HandleHibernateKey=hibernate
#HandleLidSwitch=suspend
PowerKeyIgnoreInhibited=yes
SuspendKeyIgnoreInhibited=yes
HibernateKeyIgnoreInhibited=yes
#LidSwitchIgnoreInhibited=yes
#IdleAction=ignore
#IdleActionSec=30min