Fix Internal Error with docker 25.0.0 (bsc#1222668, gh##32)

due to VirtualSize removal from images API

https://docs.docker.com/engine/release-notes/25.0/
https://docs.docker.com/engine/api/v1.45/#tag/Image/operation/ImageList

src/lib/ydocker/main_dialog.rb

@@ -275,7 +275,7 @@ def images_items
             tag,
             image.id.slice(0, 12),
             DateTime.strptime(image.info["Created"].to_s, "%s").to_s,
-            Y2Storage::DiskSize.new(image.info["VirtualSize"]).to_human_string
+            Y2Storage::DiskSize.new(image.info["Size"]).to_human_string
           )
         end
       end