Connection shutdown after system time changed.

[ditupao]

In 2.2.1, we check u-test for twice, to confirm connection is lost.

cs104_slave.c:2410

    if (self->outstandingTestFRConMessages > 2) {
            DEBUG_PRINT("Timeout for TESTFR CON message\n");

            /* close connection */
            timeoutsOk = false;

When system is changed to some time later, it cause system sending a u-test frame.
Tcp connection will not be shutdown immediately.

When updated to 2.3.1, this part is rewritten.

cs104_slave.c:2523

     if (checkTestFRConTimeout(self, currentTime)) {
            DEBUG_PRINT("CS104 SLAVE: Timeout for TESTFR CON message\n");

            /* close connection */
            timeoutsOk = false;

When system is changed to some time later, checkTestFRConTimeout returns true.
Tcp connection will be shutdown immediately.

I think we need add a conter to ensure connection is lost.
Just like this :

     if (checkTestFRConTimeout(self, currentTime)) {
            DEBUG_PRINT("CS104 SLAVE: Timeout for TESTFR CON message\n");
            self->unconfirmedTestFRConMessages ++;
            if (self->unconfirmedTestFRConMessages > 2) {
                 /* close connection */
                timeoutsOk = false;
            }