Fix double URL-encoded image paths
Some images with URL-encodable characters in their paths (the image-specific part of the URL, not including the server's root URL). This is true for 45 images in the 500 manifests Horae corpus.
https://adore.ugent.be/IIIF/images/archive.ugent.be%3A7F0C4994-C579-11E7-8646-155E6EE4309A%3ADS.179/info.json
would be modified into https://adore.ugent.be/IIIF/images/archive.ugent.be%253A7F0C4994-C579-11E7-8646-155E6EE4309A%253ADS.179/info.json
(%25
instead of %
)