sources: factor out Source::URL::Skeb.

app/models/artist_url.rb

@@ -118,7 +118,7 @@ class ArtistURL < ApplicationRecord
   end
 
   def self.normalize_url(url)
-    Danbooru::URL.parse(url)&.to_s.presence || url
+    Danbooru::URL.parse(url)&.to_normalized_s.presence || url
   end
 
   def url=(url)

app/models/upload.rb

@@ -70,7 +70,7 @@ class Upload < ApplicationRecord
     class_methods do
       # percent-encode unicode characters in the URL
       def normalize_source(url)
-        Danbooru::URL.parse(url)&.to_s.presence || url
+        Danbooru::URL.parse(url)&.to_normalized_s.presence || url
       end
     end
   end