end-session-dialog: Wait 60 seconds (not 61) before auto-confirming

This source is added via g_timeout_add(). As a second has already passed, decrement first and then update the dialog text.

Signed-off-by: Evangelos Ribeiro Tzaras devrtz@fortysixandtwo.eu

Video from before this change:

phosh-end-session

(I didn't bother making another video with this change)