URL not decoded correctly using Decodable Swift 4 protocol

I receive this url string from the server:

{
   "image":"http:\/\/site.se\/wp-content\/uploads\/2012\/09\/Hidl\u00f8gsma.jpg"
}

the value is:

http://site.se/wp-content/uploads/2012/09/Hidløgsma.jpg

Using the Swift 4 Decodable protocol fails with error:

Invalid URL string.

is there a way to make it work with the above string ?