require LT_OUTPUT (this should fix the libtool 2.* problem.

thanks to felix for excessive testing...

[[Imported from SVN: r5409]]

bin/dunecontrol

@@ -632,7 +632,7 @@ AC_DEFUN([DUNE_CHECK_MOD_DEPENDENCIES], [
   AC_REQUIRE([AC_PROG_CXXCPP])
   AC_REQUIRE([AC_PROG_LIBTOOL])
   m4_ifdef([AC_LIBTOOL_LANG_CXX_CONFIG],[AC_LIBTOOL_LANG_CXX_CONFIG])
-  LT_OUTPUT
+  AC_REQUIRE([LT_OUTPUT])
 EOF
       ### initialize AM_CONDITIONAL for suggestions that were not found
       for name in $(eval echo \$SUGS_$mainmod); do