applied patch from Derek Poon fixing bug #310692 Daniel

* valid.c: applied patch from Derek Poon fixing bug #310692
Daniel
diff --git a/configure.in b/configure.in
index 9b16c4c..6485e60 100644
--- a/configure.in
+++ b/configure.in
@@ -738,6 +738,7 @@
     if test "$with_minimum" != "yes"
     then
 	if test "${with_mem_debug}" = "" ; then
+	    echo Activating memory debugging
 	    with_mem_debug="yes"
 	    with_run_debug="yes"
 	fi