build system updated

ax_init_standard_project.m4

@@ -1,4 +1,4 @@
-## @id $Id$
+## @id $Id: ax_init_standard_project.m4 204 2016-09-29 18:29:53Z marc $
 
 ##       1         2         3         4         5         6         7         8
 ## 45678901234567890123456789012345678901234567890123456789012345678901234567890
@@ -962,8 +962,8 @@ AC_DEFUN([AX_PKG_CHECK], [
 #    $2 = pathes to search for
 AC_DEFUN([AX_REQUIRE_HEADER], [
   AC_CHECK_HEADER($1, [], [
+    found=0
     if test -n "$2"; then
-      found=0
       for d in $2; do
         if test -f "${d}/$1"; then
           AC_MSG_NOTICE([found file ${d}/$1])