PropertiesChanged signal is missing in Client::DBus::PropertiesInterface

[Kaffeine]

The modern approach to use the org.freedesktop.DBus.Properties.PropertiesChanged signal for property changed notification is not supported on the client side.

• Channel.Interface.RoomConfig1
• Channel.Interface.Subject2
• Channel.Interface.CaptchaAuthentication1

See also: https://github.com/TelepathyIM/telepathy-glib/commit/5894586c33dc082116049e4f136838d039285508