Handle users that are not allowed to log in, in the greeter [$50]

[Cleiton Floss]

First of all, I created 1 account to test this plug and limited that account to only log-in on weekends from 15:00 to 17:00.

The problem is, on pantheon-greeter when I select the restricted account in a day that is not allowed to log-in, it starts to make the animation to when I type the incorrect password, it keeps sliding from left to right and I can't select another account.

[Danielle Foré (danrabbit)]

https://www.bountysource.com/issues/27328128-handle-users-that-are-not-allowed-to-log-in-in-the-greeter

[Zisu Andrei (matzipan)]

The attached branch also fixes this issue. Described as this: "It also fixes bug #1447165 by adding the not_authenticated method and calling it only in the LigthDM authentication callback instead of calling it every time a message is recieved (since fprintd sends messages, this was causing the greeter to invoke shake() continuously)."

[David Hewitt (davidmhewitt)]

Closing this as the linked branch resolved the issue.