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[$removeChild](this.break);
      this.break = null;
    }
    if (this.presence === "hidden" || this.presence === "inactive") {
      return HTMLResult.EMPTY;
    }
    if (
      this.breakBefore.children.length > 1 ||
      this.breakAfter.children.length > 1
    ) {
      
      
      warn(
        "XFA - Several breakBefore or breakAfter in subforms: please file a bug."
      );
    }
    if (this.breakBefore.children.length >= 1) {
      const breakBefore = this.breakBefore.children[0];
      if (!breakBefore[$extra]) {
        
        breakBefore[$extra] = true;
        return HTMLResult.breakNode(breakBefore);
      }
    }
    if (this[$extra] && this[$extra].afterBreakAfter) {
      return HTMLResult.EMPTY;
    }
    
    fixDimensions(this);