If a MatsSocket only performs subscribe, no other message sending, then sub was never sent to server

[stolsvik]

The problem was that the "SUB" message was not considered "information bearing", and thus the MatsSocket would never open and connect.

This was probably not a big problem in actual usage scenarios as one probably very seldom would only subscribe, but also at least send a "what is the latest news"-type message. However, it nevertheless it caused some developers to use a considerable time on debugging why they never got any published messages from the server.