json4lua: adapted to the new lua-conf.in

lua/json4lua/json4lua.conf

@@ -2,7 +2,7 @@
 # This copyright note is auto-generated by ./scripts/Create-CopyPatch.
 #
 # Filename: package/.../json4lua/json4lua.conf
-# Copyright (C) 2008 The OpenSDE Project
+# Copyright (C) 2008 - 2009 The OpenSDE Project
 #
 # More information can be found in the files COPYING and README.
 #
@@ -16,10 +16,10 @@ srcdir=json
 makeopt=
 makeinstopt=
 
-json_install()
-{
-	mkdir -p "$root$pkgdatadir/json"
-	cp -v *.lua "$root$pkgdatadir/json/"
+json_install() {
+	local x="$root$luadatadir/json"
+	mkdir -p "$x"
+	cp -v *.lua "$x"
 }
 
 hook_add postmake 5 'json_install'