[m4-common] Update autoconf-archive

[Sébastien Wilmet <swilmet src gnome org>]

commit 20e62d808dab2000658f0e03363cf669f9b3a499
Author: Sébastien Wilmet <swilmet gnome org>
Date:   Sun Oct 15 12:04:10 2017 +0200

    Update autoconf-archive
    
    There are more flags to AX_COMPILER_FLAGS.

 autoconf-archive |    2 +-
 1 files changed, 1 insertions(+), 1 deletions(-)
---
diff --git a/autoconf-archive b/autoconf-archive
index cfa14e9..aea1451 160000
--- a/autoconf-archive
+++ b/autoconf-archive
@@ -1 +1 @@
-Subproject commit cfa14e9ac5d874abfc19e5d33eb7a1bbb9c4e899
+Subproject commit aea14513e483806fc1cac0216af0e5e82afa4dcd