config: remove customize_new_user config option.

app/models/user.rb

@@ -80,7 +80,6 @@ class User < ApplicationRecord
   validates_presence_of :comment_threshold
   before_validation :normalize_blacklisted_tags
   before_create :promote_to_admin_if_first_user
-  before_create :customize_new_user
   has_many :artists, foreign_key: :creator_id
   has_many :artist_versions, foreign_key: :updater_id
   has_many :artist_commentary_versions, foreign_key: :updater_id
@@ -256,10 +255,6 @@ class User < ApplicationRecord
       end
     end
 
-    def customize_new_user
-      Danbooru.config.customize_new_user(self)
-    end
-
     def level_string_was
       level_string(level_was)
     end