update lua file headers

dat/nhlib.lua

@@ -1,4 +1,6 @@
-
+-- NetHack nhlib.lua	$NHDT-Date: 1652196140 2022/05/10 15:22:20 $  $NHDT-Branch: NetHack-3.7 $:$NHDT-Revision: 1.4 $
+--	Copyright (c) 2021 by Pasi Kallinen
+-- NetHack may be freely redistributed.  See license for details.
 -- compatibility shim
 math.random = function(...)
    local arg = {...};