screenShield: fix lifting when inserting smartcard

If a user inserts the smartcard they logged in with into the system,
it's supposed to lift the shield and prompt for pin.  That doesn't
happen because the parameter list of the smartcard-inserted signal
handler is wrong.

This commit fixes that.

https://bugzilla.gnome.org/show_bug.cgi?id=726262
util: fix "login card" smartcard detection on unlock screen

We only want to react to the card the user logged in with, at
the unlock screen.  We check "at the unlock screen" by checking
the "reauthenticating" state variable.  That variable is the
wrong one, though. It gets set too late, and in some cases, gets
set at the login screen, too.  We should be checking this._reauthOnly
instead.

This commit fixes that.

https://bugzilla.gnome.org/show_bug.cgi?id=726262
Updated German translation