[gnome-applets/wip/muktupavels/werror] drivemount: fix -Wformat-nonliteral warning

[Alberts Muktupāvels <muktupavels src gnome org>]

commit 97dfdb249ab90be8c1b7120d6f2f281dc9a13824
Author: Alberts Muktupāvels <alberts muktupavels gmail com>
Date:   Sat Apr 4 22:05:21 2020 +0300

    drivemount: fix -Wformat-nonliteral warning

 gnome-applets/drivemount/drive-button.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)
---
diff --git a/gnome-applets/drivemount/drive-button.c b/gnome-applets/drivemount/drive-button.c
index 65d617b7a..227bc1ed3 100644
--- a/gnome-applets/drivemount/drive-button.c
+++ b/gnome-applets/drivemount/drive-button.c
@@ -546,8 +546,8 @@ open_drive (DriveButton *self, GtkWidget *item)
                                                     _("Cannot start Nautilus File Manager"));
          if (error)
              gtk_message_dialog_format_secondary_text (GTK_MESSAGE_DIALOG (dialog),
-                                                       error->message,
-                                                       NULL);
+                                                       "%s",
+                                                       error->message);
          else
              gtk_message_dialog_format_secondary_text (GTK_MESSAGE_DIALOG (dialog),
                                                        "%s", _("Could not find Nautilus"));