[ghex/wip/davidk/format-string] appwindow: Fix format string warning

[David King <davidk src gnome org>]

commit 3d35359f3a12b6abb4a3d8a12a0f39b7221be408
Author: David King <amigadave amigadave com>
Date:   Mon Jan 10 09:35:07 2022 +0000

    appwindow: Fix format string warning
    
    ../src/ghex-application-window.c: In function ‘close_doc_confirmation_dialog’:
    ../src/ghex-application-window.c:523:25: error: format not a string literal and no format arguments 
[-Werror=format-security]
      523 |                         message);
          |                         ^~~~~~~

 src/ghex-application-window.c | 1 +
 1 file changed, 1 insertion(+)
---
diff --git a/src/ghex-application-window.c b/src/ghex-application-window.c
index f1a7145..34cf802 100644
--- a/src/ghex-application-window.c
+++ b/src/ghex-application-window.c
@@ -520,6 +520,7 @@ close_doc_confirmation_dialog (GHexApplicationWindow *self,
                        GTK_DIALOG_MODAL | GTK_DIALOG_DESTROY_WITH_PARENT,
                        GTK_MESSAGE_QUESTION,
                        GTK_BUTTONS_NONE,
+                       "%s",
                        message);
        g_free (message);