[gdm] configure: bump to 3.31.91

[Ray Strode <halfline src gnome org>]

commit e4a9c7edeca45b51d568dbec6900ef9f359b364c
Author: Ray Strode <rstrode redhat com>
Date:   Tue Feb 26 15:15:59 2019 -0500

    configure: bump to 3.31.91

 configure.ac | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)
---
diff --git a/configure.ac b/configure.ac
index c7454ffa..4502d267 100644
--- a/configure.ac
+++ b/configure.ac
@@ -1,7 +1,7 @@
 
 AC_PREREQ([2.60])
 AC_INIT([gdm],
-        [3.31.4],
+        [3.31.91],
         [http://bugzilla.gnome.org/enter_bug.cgi?product=gdm])
 
 AC_CONFIG_SRCDIR([daemon/gdm-manager.c])