Use AC_CONFIG_HEADERS
Use AC_CONFIG_HEADERS as recommended by the Gentoo team.
Thanks to David Heidelberger and Kensington.
--- a/mcabber/configure.ac Wed May 15 13:32:42 2013 +0300
+++ b/mcabber/configure.ac Sun Sep 29 17:55:17 2013 +0200
@@ -5,8 +5,8 @@
AC_INIT([mcabber],[0.10.3-dev],[mcabber@lilotux.net])
XC_AUTOMAKE
AC_CONFIG_SRCDIR([mcabber])
-AM_CONFIG_HEADER(mcabber/config.h)
-AC_CONFIG_HEADER(include/config.h)
+AC_CONFIG_HEADERS([mcabber/config.h])
+AC_CONFIG_HEADERS([include/config.h])
AC_PROG_LIBTOOL
AC_PROG_RANLIB