media assets: fix tagged filenames option.

Fix the `enable_seo_post_urls` config option not being respected. This
option controls whether filenames in image URLs contain the tags. This
option requires URLs rewrites in Nginx to work so it's disabled by
default.

app/logical/storage_manager.rb

@@ -11,16 +11,14 @@
 class StorageManager
   class Error < StandardError; end
 
-  attr_reader :base_url, :base_dir, :tagged_filenames
+  attr_reader :base_url, :base_dir
 
   # Initialize a storage manager object.
   # @param base_url [String] the base URL where images are stored (ex: "https://cdn.donmai.us/")
   # @param base_dir [String] the base directory where images are stored (ex: "/var/www/danbooru/public/images")
-  # @param tagged_filenames [Boolean] whether image URLs can include tags
-  def initialize(base_url: nil, base_dir: nil, tagged_filenames: Danbooru.config.enable_seo_post_urls)
+  def initialize(base_url: nil, base_dir: nil)
     @base_url = base_url.to_s.chomp("/")
     @base_dir = base_dir.to_s
-    @tagged_filenames = tagged_filenames
   end
 
   # Store the given file at the given path. If a file already exists at that

app/models/media_asset.rb

@@ -67,6 +67,7 @@ class MediaAsset < ApplicationRecord
         "/images/download-preview.png"
       else
         slug = "__#{slug}__" if slug.present?
+        slug = nil if !Danbooru.config.enable_seo_post_urls
         "/#{variant}/#{md5[0..1]}/#{md5[2..3]}/#{slug}#{file_name}"
       end
     end