cli: exit from main loop after 'quit' editor command

When we stop processing the editor command loop (after a 'quit'
command) we must quit the GLib main loop.

https://bugzilla.redhat.com/show_bug.cgi?id=1517401

clients/cli/connections.c

@@ -7563,6 +7563,8 @@ editor_menu_main (NmCli *nmc, NMConnection *connection, const char *connection_t
 	g_free (menu_ctx.valid_props_str);
 	g_weak_ref_clear (&weak);
 
+	quit ();
+
 	/* Save history file */
 	save_history_cmds (nm_connection_get_uuid (connection));