[PATCH] Cygwin: Update configure.ac to use AC_CONFIG_HEADERS

[Jon Turney]

This avoids warning with autoconf >= 2.70:

  configure.ac:47: warning: The macro `AC_CONFIG_HEADER' is obsolete.

AC_CONFIG_HEADERS has been supported since before autconf 2.59, the
minimum version we can be using, controlled by AC_PREREQ.
---
 winsup/configure.ac | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/winsup/configure.ac b/winsup/configure.ac
index 9a11411ab..79e78a5fc 100644
--- a/winsup/configure.ac
+++ b/winsup/configure.ac
@@ -44,7 +44,7 @@ AC_ARG_WITH([cross-bootstrap],[AS_HELP_STRING([--with-cross-bootstrap],[do not b
 
 AC_CYGWIN_INCLUDES
 
-AC_CONFIG_HEADER(cygwin/config.h)
+AC_CONFIG_HEADERS([cygwin/config.h])
 
 AC_CHECK_TOOL(AR, ar, ar)
 AC_CHECK_TOOL(AS, as, as)
-- 
2.34.1