[atk] configure.ac: Stop using deprecated GNOME-specific autoconf macros

[Javier Jardón <jjardon src gnome org>]

commit 93ab14e7dd0036243269dedd5569cdb5cc26f513
Author: Javier Jardón <jjardon gnome org>
Date:   Wed Feb 18 12:21:33 2015 +0000

    configure.ac: Stop using deprecated GNOME-specific autoconf macros
    
    This will eventually be replaced by AX_COMPILER_FLAGS
    
    https://bugzilla.gnome.org/show_bug.cgi?id=744413

 configure.ac |    2 --
 1 files changed, 0 insertions(+), 2 deletions(-)
---
diff --git a/configure.ac b/configure.ac
index b190251..95688ab 100644
--- a/configure.ac
+++ b/configure.ac
@@ -259,8 +259,6 @@ case "$host" in
 esac
 AC_SUBST(ATK_HIDDEN_VISIBILITY_CFLAGS)
 
-GNOME_COMPILE_WARNINGS([maximum])
-
 AC_CONFIG_FILES([
 Makefile
 po/Makefile.in