won't be accepted until the server app actually requires an I2PServerSocket
from the I2PSocketManager.
It allows both to add a little bit of functionality, and to fix a nasty bug: it
was possible to hang an app that connects through the I2PSocketManager but
actually doesn't accept() connections (if 2 connection requests were sent
to the app, the I2PSocketManager got stuck waiting forever on
I2PServerSocketImpl.getNewSocket()).