[EJBCLIENT-109] At MethodInvocationResponseHandler$MethodInvocationRespo...

...nseProducer.discardResult: skip the bytes in the response, and close the DataInputStream afterwards

This is the fix for EJBCLIENT-109.

The only thing I am uncertain about the fix is the treatment of the exception, if I should log it as error or not.
If this needs to be changed, please let me know.