Revert "nmsg/isc/Makefile.am: link the isc message module against libustr"
Revert "nmsg/isc/Makefile.am: link the isc message module against libustr"

This reverts commit 76f85fe5334c6ec1a7f440261404e3214e21a40e.

hstern/nmsg,hstern/nmsg,hstern/nmsg,hstern/nmsg,hstern/nmsg