Fix -Wshorten-64-to-32 warning

[orangefour]

I fixed a couple of warnings that were popping out because of qint64 to int conversion

void RequestPrototype::handleUploadProgress(qint64 sent, qint64 total)
{
    emitEvent(EVENT_PROGRESS, createProgressEvent(true, sent, total));
    emit progress(sent, total); < ---- WARNING
}

void RequestPrototype::handleDownloadProgress(qint64 received, qint64 total)
{
    emitEvent(EVENT_PROGRESS, createProgressEvent(false, received, total));
    emit progress(received, total); < ---- WARNING
}