autoconf/check_libprotobuf-c_sizeof.m4: use libprotobuf_c CFLAGS / LDFLAGS / LIBS
autoconf/check_libprotobuf-c_sizeof.m4: use libprotobuf_c CFLAGS / LDFLAGS / LIBS

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