Imperfect fix no image if user is not able to download

Set element_url to empty string if the key doesn't exist

Author: Renarde-dev

lib/models/image_model.dart

@@ -48,7 +48,7 @@ class ImageModel {
         dateCreation = json['date_creation'],
         dateAvailable = json['date_available'],
         pageUrl = json['page_url'],
-        elementUrl = json['element_url'],
+        elementUrl = json.containsKey("element_url") ? json['element_url'] : "",
         derivatives = Derivatives.fromJson(json['derivatives']),
         categories = json['categories'] ?? [],
         tags = json['tags']

lib/views/image/image_page.dart

@@ -480,9 +480,8 @@ class _ImagePageState extends State<ImagePage> {
       builder: (context, index) {
         final ImageModel image = _imageList[index];
 
-        String imageUrl = '';
-        if (Preferences.getImageFullScreenSize == 'full') {
-          imageUrl = image.elementUrl;
+        String imageUrl = image.elementUrl;
+        if (Preferences.getImageFullScreenSize == 'full' && imageUrl.isNotEmpty) {
           imageUrl = HtmlUnescape().convert(imageUrl);
         } else {
           imageUrl = image.getDerivativeFromString(Preferences.getImageFullScreenSize)?.url ?? '';