Fix type check errors for Image source

The parent class does not accept an extent on its options. Also
check that the image is an img or video tag before setting the
source as Canvas does not have the src property.

src/ol/source/Image.js

@@ -91,7 +91,6 @@ class ImageSource extends Source {
   constructor(options) {
     super({
       attributions: options.attributions,
-      extent: options.extent,
       projection: options.projection,
       state: options.state
     });
@@ -232,7 +231,10 @@ class ImageSource extends Source {
  * @param {string} src Source.
  */
 export function defaultImageLoadFunction(image, src) {
-  image.getImage().src = src;
+  const img = image.getImage();
+  if (img instanceof HTMLImageElement || img instanceof HTMLVideoElement) {
+    img.src = src;
+  }
 }