Attach (recommended) or Link to PDF file here:
https://guichet.public.lu/dam-assets/catalogue-formulaires/tva/tva-option-aic-pers-morales/tva-option-aic-pers-morale-DE.pdf

Configuration:
- Web browser and its version: Firefox Nightly 91.0a1 (2021-06-26) (64-bit)
- Operating system and its version: Windows 10.0.19043.1052
- PDF.js version: N/A

Steps to reproduce the problem:
1. enableXFA in Firefox Nightly
2. Open form

What is the expected behavior? (add screenshot)
Header image is scaled properly
![image](https://user-images.githubusercontent.com/7104454/123525954-905d1f00-d6a2-11eb-840e-be30eee395e1.png)

What went wrong? (add screenshot)
Image is scaled to fit
![image](https://user-images.githubusercontent.com/7104454/123525957-96530000-d6a2-11eb-9991-bf7f37c6f1a5.png)


} else {
      style.fill = "transparent";
    }
    style.strokeWidth = measureToString(
      edge.presence === "visible" ? Math.round(edge.thickness) : 0
    );
    style.stroke = edgeStyle.color;
    let arc;
    const attributes = {
      xmlns: SVG_NS,
      style: {
        position: "absolute",
        width: "100%",
        height: "100%",
      },
    };
    if (this.startAngle === 0 && this.sweepAngle === 360) {
      arc = {
        name: "ellipse",
        attributes: {
          xmlns: SVG_NS,
          cx: "50%",
          cy: "50%",
          rx: "50%",
          ry: "50%",
          style,
        },
      };
    } else {
      const startAngle = (this.startAngle * Math.PI) / 180;