FIX: Reviewables should not be created for users until they are active

Conversely, if a user is deactivated the reviewable should automatically
be rejected.

Before this fix, if a user was not active they'd still show in the
review queue but without an "Approve" button which was confusing.

app/models/user.rb

@@ -116,7 +116,6 @@ class User < ActiveRecord::Base
   after_create :set_random_avatar
   after_create :ensure_in_trust_level_group
   after_create :set_default_categories_preferences
-  after_create :create_reviewable
 
   before_save :update_username_lower
   before_save :ensure_password_is_hashed
@@ -898,10 +897,15 @@ class User < ActiveRecord::Base
     else
       self.update!(active: true)
     end
+    create_reviewable
   end
 
-  def deactivate
+  def deactivate(performed_by)
     self.update!(active: false)
+
+    if reviewable = ReviewableUser.pending.find_by(target: self)
+      reviewable.perform(performed_by, :reject)
+    end
   end
 
   def change_trust_level!(level, opts = nil)
@@ -1242,14 +1246,7 @@ class User < ActiveRecord::Base
     return unless SiteSetting.must_approve_users? || SiteSetting.invite_only?
     return if approved?
 
-    reviewable = ReviewableUser.needs_review!(target: self, created_by: Discourse.system_user, reviewable_by_moderator: true)
-    reviewable.add_score(
-      Discourse.system_user,
-      ReviewableScore.types[:needs_approval],
-      force_review: true
-    )
-
-    reviewable
+    Jobs.enqueue(:create_user_reviewable, user_id: self.id)
   end
 
   def create_user_stat