update backend/dvadmin/system/views/file_list.py.

修复lssuess问题(https://gitee.com/huge-dream/django-vue3-admin/issues/IA8ROD)
- 附件管理无法打开文件和图片
- 富文本无法打开文件和图片

Signed-off-by: 木子-李 <1537080775@qq.com>

backend/dvadmin/system/views/file_list.py

@@ -15,8 +15,8 @@ class FileSerializer(CustomModelSerializer):
     url = serializers.SerializerMethodField(read_only=True)
 
     def get_url(self, instance):
-        # return 'media/' + str(instance.url)
+        base_url = f"{self.request.scheme}://{self.request.get_host()}/"
-        return instance.file_url or (f'media/{str(instance.url)}')
+        return base_url + (instance.file_url or (f'media/{str(instance.url)}'))
 
     class Meta:
         model = FileList