[gnome-boxes/release-gnome-3-36-2: 7/10] machine: Only dismiss existing notifications

[Felipe Borges <felipeborges src gnome org>]

commit d518dcc69205e1ed44be573a2b3ff49a4bd745c0
Author: Felipe Borges <felipeborges gnome org>
Date:   Thu Mar 26 12:24:37 2020 +0100

    machine: Only dismiss existing notifications
    
    AuthNotifications concern mostly remote connections. So if a libvirt
    machine creation is interrupted, we don't need to clean it up. Only
    for Remote Machines

 src/machine.vala | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)
---
diff --git a/src/machine.vala b/src/machine.vala
index d86a06b7..d3ed13f0 100644
--- a/src/machine.vala
+++ b/src/machine.vala
@@ -760,8 +760,10 @@ private async void delete_auth_credentials () {
             yield Secret.password_clear (secret_auth_schema, null,
                                          "gnome-boxes-machine-uuid", config.uuid);
 
-            auth_notification.dismiss ();
-            auth_notification = null;
+            if (auth_notification != null) {
+                auth_notification.dismiss ();
+                auth_notification = null;
+            }
         } catch (GLib.Error error) {
             debug ("Failed to delete credentials for machine %s: %s", config.uuid, error.message);
         }