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)


this.reasons = new XFAObjectArray();
    this.rectangle = new XFAObjectArray();
    this.ref = new XFAObjectArray();
    this.script = new XFAObjectArray();
    this.setProperty = new XFAObjectArray();
    this.signData = new XFAObjectArray();
    this.signature = new XFAObjectArray();
    this.signing = new XFAObjectArray();
    this.solid = new XFAObjectArray();
    this.speak = new XFAObjectArray();
    this.stipple = new XFAObjectArray();
    this.subform = new XFAObjectArray();
    this.subformSet = new XFAObjectArray();
    this.subjectDN = new XFAObjectArray();
    this.subjectDNs = new XFAObjectArray();
    this.submit = new XFAObjectArray();
    this.text = new XFAObjectArray();
    this.textEdit = new XFAObjectArray();
    this.time = new XFAObjectArray();
    this.timeStamp = new XFAObjectArray();
    this.toolTip = new XFAObjectArray();
    this.traversal = new XFAObjectArray();
    this.traverse = new XFAObjectArray();
    this.ui = new XFAObjectArray();
    this.validate = new XFAObjectArray();
    this.value = new XFAObjectArray();
    this.variables = new XFAObjectArray();
  }
}
class Radial extends XFAObject {