Clear all optionally created widget pointer in priv. Initially priv is

Clear all optionally created widget pointer in priv. Initially priv is

2009-03-10  Alexander Larsson  <alexl@redhat.com>

        * gtk/gtkmountoperation.c:
        (gtk_mount_operation_ask_password):
	Clear all optionally created widget pointer in priv. Initially
	priv is cleared so thats ok, but on a second call we may have
	leftovers from previous calls which is problematic if for instance
	we asked for the user the first time and not the second, then we
	will access the old priv->username_entry.

svn path=/trunk/; revision=22496