Made stream_stat() ignore StreamUtil::getSize() result if it is 0 to …

[DylanDonkersgoed]

…fix issue #21

[AbhayPai]

I faced similar issue, what i did was just to put default stat

        // Use the size of our handle, since it could have been written to or
        // truncated.
        $stream_util_size = StreamUtil::getSize($this->handle);
        if (!empty($stream_util_size)) {
            // Only set size if stream_util_size is available or
            // just send original file metadata.
            $stat['size'] = $stat[7] = $stream_util_size;
        }