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 loadStyles(styles);
  }
  function inlineAnnotationImages(images) {
    var imagePromises = [];
    for (var i = 0, ii = images.length; i < ii; i++) {
      var imagePromise = new Promise(function (resolve, reject) {
        var xhr = new XMLHttpRequest();
        xhr.responseType = "blob";
        xhr.onload = function () {
          var reader = new FileReader();
          reader.onloadend = function () {
            resolve(reader.result);
          };
          reader.readAsDataURL(xhr.response);
        };
        xhr.onerror = function (e) {
          reject(new Error("Error fetching inline annotation image " + e));
        };
        xhr.open("GET", images[i].src);
        xhr.send();
      });
      imagePromises.push(imagePromise);
    }
    return imagePromises;
  }
  
  function rasterizeAnnotationLayer(