models: set more creator names explicitly.

Set creators explicitly for bans, BURs, comment votes, and posts.

app/models/ban.rb

@@ -8,7 +8,6 @@ class Ban < ApplicationRecord
   belongs_to :banner, :class_name => "User"
   validate :user_is_inferior
   validates_presence_of :reason, :duration
-  before_validation :initialize_banner_id, :on => :create
 
   scope :unexpired, -> { where("bans.expires_at > ?", Time.now) }
   scope :expired, -> { where("bans.expires_at <= ?", Time.now) }
@@ -50,10 +49,6 @@ class Ban < ApplicationRecord
     end
   end
 
-  def initialize_banner_id
-    self.banner_id = CurrentUser.id if self.banner_id.blank?
-  end
-
   def user_is_inferior
     if user
       if user.is_admin?