Don't store owner or group in our release's tar archive

Set owner and group to ID 0 and don't store the same either. This is
done so the archive will not show the username of the user who created
the release.

tools/build/Makefile-Moar.in

@@ -76,7 +76,7 @@ release: manifest
 	bash -c '[ "$$(cat VERSION)" == "$(VERSION)" ] || ( echo -e "\nVersion on command line and in VERSION file differ\n"; exit 1 )'
 	[ -d nqp-$(VERSION) ] || ln -s . nqp-$(VERSION)
 	$(PERL) -ne 'print "nqp-$(VERSION)/$$_"' MANIFEST |\
-	    tar -zcv -T - -f nqp-$(VERSION).tar.gz
+	    tar -zcv --owner=0 --group=0 --numeric-owner -T - -f nqp-$(VERSION).tar.gz
 	rm nqp-$(VERSION)
 
 distclean: realclean