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)


return new Encrypt(attrs);
  }
  static encryptData(attrs) {
    return new EncryptData(attrs);
  }
  static encryption(attrs) {
    return new Encryption(attrs);
  }
  static encryptionMethod(attrs) {
    return new EncryptionMethod(attrs);
  }
  static encryptionMethods(attrs) {
    return new EncryptionMethods(attrs);
  }
  static event(attrs) {
    return new Event(attrs);
  }
  static exData(attrs) {
    return new ExData(attrs);
  }
  static exObject(attrs) {
    return new ExObject(attrs);
  }
  static exclGroup(attrs) {
    return new ExclGroup(attrs);
  }
  static execute(attrs) {
    return new Execute(attrs);
  }
  static extras(attrs) {