config: remove unused config options.

config/danbooru_default_config.rb

@@ -52,10 +52,6 @@ module Danbooru
       "https://github.com/danbooru/danbooru"
     end
 
-    def commit_url(hash)
-      "#{source_code_url}/commit/#{hash}"
-    end
-
     def issues_url
       "#{source_code_url}/issues"
     end
@@ -304,16 +300,6 @@ module Danbooru
       []
     end
 
-    # DeviantArt login cookies. Login to DeviantArt and extract these from the browser.
-    # https://github.com/danbooru/danbooru/issues/4219
-    def deviantart_cookies
-      {
-        userinfo: "XXX",
-        auth_secure: "XXX",
-        auth: "XXX"
-      }.to_json
-    end
-
     def pixiv_login
       nil
     end
@@ -471,11 +457,6 @@ module Danbooru
     def iqdbs_server
     end
 
-    # AWS config options
-    def aws_region
-      "us-east-1"
-    end
-
     def aws_credentials
       Aws::Credentials.new(Danbooru.config.aws_access_key_id, Danbooru.config.aws_secret_access_key)
     end