configure: replace deprecated AM_CONFIG_HEADER with AC_CONFIG_HEADERS

AM_CONFIG_HEADER has been removed in the just-released automake 1.13:
https://lists.gnu.org/archive/html/automake/2012-12/msg00038.html

https://bugzilla.gnome.org/show_bug.cgi?id=690881

diff --git a/configure.ac b/configure.ac
index f566241..1063828 100644 (file)
--- a/configure.ac
+++ b/configure.ac
@@ -20,7 +20,7 @@ dnl can autoconf find the source ?
 AC_CONFIG_SRCDIR([gst/gst.c])
 
 dnl define the output header for config
-AM_CONFIG_HEADER([config.h])
+AC_CONFIG_HEADERS([config.h])
 
 dnl AM_MAINTAINER_MODE only provides the option to configure to enable it
 AM_MAINTAINER_MODE([enable])