Propagate IO exceptions in TeeServletInputStream - #29

When the TeeFilter is configured as described in Capturing incoming HTTP requests and outgoing responses any IO exceptions which may occur while reading the HTTP request body are not propagated (see TeeServletInputStream):

private void duplicateInputStream(HttpServletRequest request) {
    ServletInputStream originalSIS = null;
    try {
        originalSIS = request.getInputStream();
        inputBuffer = consumeBufferAndReturnAsByteArray(originalSIS);
        this.in = new ByteArrayInputStream(inputBuffer);
    } catch (IOException e) {
        e.printStackTrace();
    } finally {
        closeStream(originalSIS);
    }
}

All IO exceptions are caught and the exception stack trace gets printed to the console. In this case this.in never gets assigned a value / is still set to null.

If a servlet later tries to read from the ServletInputStream a NullPointerException is thrown instead:

Caused by: java.lang.NullPointerException: Cannot invoke "java.io.InputStream.read()" because "this.in" is null
    at ch.qos.logback.access.common.servlet.TeeServletInputStream.read(TeeServletInputStream.java:49)
    ...

My change propagates the IO exception to the caller when a servlet attempts to read from the stream.

Please let me know your thoughts on these changes or if you have any suggestions for improvements.