tools : engine-config confirm new passwd when changing passwd

When changing internal users password engine-config does
not ask the user to confirm the new password.

This patch asks for the password a second time and validates
it againts the previously entered password.

Change-Id: I800d1857676ad12ed084b276b3c473237280cc77
Bug-Url: https://bugzilla.redhat.com/show_bug.cgi?id=904762
Signed-off-by: Ravi Nori <rnori@redhat.com>