Incorrect number of score clients

[jorritolthuis]

The score clients label in the refbox displays 1 even if no RefereeClient is connected.

[jorritolthuis]

The refbox will always send UDP packets to 127.0.0.1. Since there is no connection, the refbox does not know if the referee client is active.
We might consider removing this number, since the current implementation does not allow for measuring the number of connected clients.