Add response buffer len check

[chinglee-iot]

Add response buffer length check to prevent receive zero byte with transport interface in receiveAndParseHttpResponse.

static HTTPStatus_t receiveAndParseHttpResponse( const TransportInterface_t * pTransport,
                                                 HTTPResponse_t * pResponse,
                                                 const HTTPRequestHeaders_t * pRequestHeaders )
{
...
    while( shouldRecv == 1U )
    {
        /* Receive the HTTP response data into the pResponse->pBuffer. */
        currentReceived = pTransport->recv( pTransport->pNetworkContext,
                                            pResponse->pBuffer + totalReceived,
                                            pResponse->bufferLen - totalReceived );