[gnome-boxes/handle-unavailable-input-sources] unattended-installer: check null keyboard

[Isaque Galdino de Araujo <igaldino src gnome org>]

commit 678fa8265fdb7f55301e594b91f007029b226628
Author: Isaque Galdino <igaldino gmail com>
Date:   Wed Nov 27 17:31:32 2019 -0300

    unattended-installer: check null keyboard

 src/unattended-installer.vala | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)
---
diff --git a/src/unattended-installer.vala b/src/unattended-installer.vala
index da91ae34..c1dfd89c 100644
--- a/src/unattended-installer.vala
+++ b/src/unattended-installer.vala
@@ -670,7 +670,7 @@ private string get_preferred_keyboard (string lang) {
                 }
             }
 
-            if (datamap.reverse_lookup (kbd_layout) != null) {
+            if (kbd_layout != null && datamap.reverse_lookup (kbd_layout) != null) {
                 return kbd_layout;
             }
         } catch (GLib.Error error) {