Do not add indices for encrypted tokens in this iteration

db/migrate/20181121101802_add_encrypted_runner_tokens_indices.rb

-# frozen_string_literal: true
-
-class AddEncryptedRunnerTokensIndices < ActiveRecord::Migration
-  include Gitlab::Database::MigrationHelpers
-
-  DOWNTIME = false
-
-  disable_ddl_transaction!
-
-  def up
-    add_concurrent_index :namespaces, :runners_token_encrypted, unique: true
-    add_concurrent_index :projects, :runners_token_encrypted, unique: true
-    add_concurrent_index :ci_runners, :token_encrypted, unique: true
-  end
-
-  def down
-    remove_concurrent_index :ci_runners, :token_encrypted
-    remove_concurrent_index :projects, :runners_token_encrypted
-    remove_concurrent_index :namespaces, :runners_token_encrypted
-  end
-end