[2.21] Connection to the hub "hangs"

[Vine]

It happens quite often, that after making an attempt to connect to the hub StrongDC++ shows the message "***Connected" in he hub window and nothing happens - list of users is not downloaded, communication with the hub is not working. StrongDC++ is not trying to reconnect, as it treats the hub as connected. This situation will last until I will manually reconnect. The reason are propably some lost packets during initial phase of connecting to the hub (or maybe even ISP policy to block DC protocol by breaking the connections somehow), nethertheless I think we shouldn't have the situation when client is assuming connection as working if it is not actually alive. What I find interesting is that if this situation (connection "hangs") happens after downoading the user list, the client recognises it after a while (I can recognise it by the fact, that I can't see any changes on the mainchat - even after sending something by myself) and it reconnects automatically (first showing the message, that the server unexpectedly closed the connection). I think we should have similar behaviour also before downloading the user list - it would be nice to have at list a timer limiting the time spent on waiting for the user list (currently it happens that the connection is hanging like this for a good few hours until I will notice it).