message: Set transparent background qr code image
diff: @@ -144,21 +144,21 @@ bool ReceiveRequestDialog::createQRCode(QLabel *label, SendCoinsRecipient _info)
  label->setText(tr("Error encoding URI into QR Code."));
  return false;
  }
  - QImage qrImage = QImage(code->width + 8, code->width + 8, QImage::Format_RGB32);
  - qrImage.fill(0xffffff);
  + QImage qrImage = QImage(code->width + 8, code->width + 8, QImage::Format_ARGB32);
  + qrImage.fill(qRgba(0, 0, 0, 0));
  unsigned char *p = code->data;
  for (int y = 0; y < code->width; y++)
  {
  for (int x = 0; x < code->width; x++)
  {
  - qrImage.setPixel(x + 4, y + 4, ((*p & 1) ? 0x0 : 0xffffff));
  + qrImage.setPixel(x + 4, y + 4, ((*p & 1) ? qRgba(0, 0, 0, 255) : qRgba(255, 255, 255, 255)));
  p++;
  }
  }
  QRcode_free(code);
  - QImage qrAddrImage = QImage(QR_IMAGE_SIZE, QR_IMAGE_SIZE+20, QImage::Format_RGB32);
  - qrAddrImage.fill(0xffffff);
  + QImage qrAddrImage = QImage(QR_IMAGE_SIZE, QR_IMAGE_SIZE+20, QImage::Format_ARGB32);
  + qrAddrImage.fill(qRgba(0, 0, 0, 0));
  QPainter painter(&qrAddrImage);
  painter.drawImage(0, 0, qrImage.scaled(QR_IMAGE_SIZE, QR_IMAGE_SIZE));
  QFont font = GUIUtil::fixedPitchFont();
  