pixiv: remove obsolete edgesuite.net rewrite rule.

This CDN hasn't been seen for several years.

ref: https://danbooru.donmai.us/forum_topics/10766

app/logical/sources/strategies/pixiv.rb

@@ -45,8 +45,7 @@ module Sources
       end
 
       def image_urls
-        image_urls_sub.
-          map {|x| rewrite_cdn(x)}
+        image_urls_sub
       rescue PixivApiClient::BadIDError
         [url]
       end
@@ -172,14 +171,6 @@ module Sources
         return metadata.pages
       end
 
-      def rewrite_cdn(x)
-        if x =~ %r{\Ahttps?:\/\/(?:\w+\.)?pixiv\.net\.edgesuite\.net}
-          return x.sub(".edgesuite.net", "")
-        end
-
-        return x
-      end
-
       # in order to prevent recursive loops, this method should not make any
       # api calls and only try to extract the illust_id from the url. therefore,
       # even though it makes sense to reference page_url here, it will only look