[discident-glib] build: Fix warnings during autogen.sh

[Bastien Nocera <hadess src gnome org>]

commit 44bbf3c07b505d3b23f7b569e3e33dfbdf38c6ad
Author: Bastien Nocera <hadess hadess net>
Date:   Mon Aug 20 10:40:03 2012 +0100

    build: Fix warnings during autogen.sh

 configure.ac |    1 +
 1 files changed, 1 insertions(+), 0 deletions(-)
---
diff --git a/configure.ac b/configure.ac
index 630765a..a6d5deb 100644
--- a/configure.ac
+++ b/configure.ac
@@ -30,6 +30,7 @@ AM_MAINTAINER_MODE
 # to make
 m4_ifdef([AM_SILENT_RULES], [AM_SILENT_RULES([yes])])
 
+AC_LANG_SOURCE
 AC_LANG_C
 AC_PROG_CC
 AC_PROG_INSTALL