Fix download card image repeatedly when file exists

[chucklu]

• [x] I have read the Contributing Guidelines
• [x] I have already signed the CLA

https://github.com/HearthSim/Hearthstone-Deck-Tracker/blob/f7b70235276a3bec055795e06801242ece1d7b9b/Hearthstone%20Deck%20Tracker/Utility/Assets/AssetDownloader.cs#L230

public bool HasAsset(T obj)
        {
            if(obj == null)
                return false;
            var filename = _getFilename(obj);
            return _succesfullyDownloadedImages.Contains(filename);
        }

The filename you get from var filename = _getFilename(obj); contains file extension, why you get files without extension. It make the HDT always download the image file again and again.

[chucklu]

@azeier @riQQ @jleclanche Any feedback?

[azeier]

Thanks for the PR! I think this was a leftover from late changes made to the AssetDownloader.

@Jonysegal can you take a quick look at this and merge it?

[chucklu]

@Jonysegal Any update?

[chucklu]

@azeier @Jonysegal Any update?