moveconfig: Avoid deprecation warning for setDaemon

Use the recommended new way of setting a thread to be a daemon.

This avoids a warning:

   DeprecationWarning: setDaemon() is deprecated, set the daemon attribute
      instead

Signed-off-by: Simon Glass <sjg@chromium.org>
diff --git a/tools/moveconfig.py b/tools/moveconfig.py
index 880a559..2f7dee8 100755
--- a/tools/moveconfig.py
+++ b/tools/moveconfig.py
@@ -2029,7 +2029,7 @@
     config_db = {}
     db_queue = queue.Queue()
     t = DatabaseThread(config_db, db_queue)
-    t.setDaemon(True)
+    t.daemon = True
     t.start()
 
     check_clean_directory()