D-Bus testing: fix glib timeout duration

The actual timeout duration was too small by a factor of 1000 (ms
versus s mismatch). Did not affect existing tests which just had their
(anyway small) timeouts triggered too soon.

test/test-dbus.py

@@ -293,7 +293,7 @@ class Timeout:
         DBusUtil.quit_events before calling loop.quit() caused
         a KeyboardInterrupt"""
         if glib and use_glib:
-            return glib.timeout_add(delay_seconds, callback)
+            return glib.timeout_add(delay_seconds * 1000, callback)
         else:
             now = time.time()
             if cls.debugTimeout: