Gajim should not PGP-sign presence until it's needed
Currently gajim PGP-signs presence before attempting to make a connection to the server. This happens even with an automatic reconnect attempt. This means, that when gpg-agent is in use, gajim causes it to pop up a passphrase prompt every minute or so as the reconnects attempts happen. There is no use in actually signing the presence since the connections fail each time. It should probably wait until a successful connection is made and sign presence just before it's actually sent