[egg-list-box] build: Fix libtool related warning

[Bastien Nocera <hadess src gnome org>]

commit 33c2f9634ac3cbec95d868b3e16fadd678f8e525
Author: Bastien Nocera <hadess hadess net>
Date:   Tue Jan 15 11:02:36 2013 +0100

    build: Fix libtool related warning
    
    warning: 'libegglistbox.la': linking libtool libraries using a non-POSIX
    archiver requires 'AM_PROG_AR' in 'configure.ac'
    
    So add it before LT_INIT so it can be used by libtool

 configure.ac |    1 +
 1 files changed, 1 insertions(+), 0 deletions(-)
---
diff --git a/configure.ac b/configure.ac
index 3eae7dc..26ac634 100644
--- a/configure.ac
+++ b/configure.ac
@@ -10,6 +10,7 @@ AM_MAINTAINER_MODE([enable])
 AC_CONFIG_FILES([Makefile
 		])
 
+AM_PROG_AR
 LT_INIT
 AC_PROG_CC
 AM_PROG_VALAC([0.16.0])