[balsa] main: Do not leak Inbox and Outbox

[Peter Bloomfield <peterb src gnome org>]

commit 27a66843d0ed56db81b0ca5335c81e1ac004c415
Author: Peter Bloomfield <PeterBloomfield bellsouth net>
Date:   Mon Feb 24 11:09:20 2020 -0500

    main: Do not leak Inbox and Outbox
    
    Balsa is about to exit, so it's just house-keeping.

 src/main.c | 2 ++
 1 file changed, 2 insertions(+)
---
diff --git a/src/main.c b/src/main.c
index 37fb0be0c..47df8181f 100644
--- a/src/main.c
+++ b/src/main.c
@@ -749,6 +749,8 @@ balsa_command_line_cb(GApplication            * application,
             libbalsa_mailbox_new_from_config("mailbox-Outbox", FALSE);
         balsa_get_stats(&unread, &unsent);
         printf("Unread: %ld Unsent: %ld\n", unread, unsent);
+        g_object_unref(balsa_app.outbox);
+        g_object_unref(balsa_app.inbox);
     } else {
         /* checking for valid config files */
         config_init();